ML20195G894
| ML20195G894 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 06/20/1988 |
| From: | LOUISIANA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20195G883 | List: |
| References | |
| NUDOCS 8806280171 | |
| Download: ML20195G894 (187) | |
Text
._ ._ - _ __ . _ _ _ . _ . ___ _ _ -
WG l
MAIN STEAM ISOLATION VALVE GUIDE RAll FAILURE g FINAL REPORT JUNE 20,1988 l
D OCKNO 82 P OCD
MSIV GUIDE RAll FAILURE m
introduction LP&L personnel on April 9,1988 found a broken gate side guide rail piece from the W K M Main Steam Isolation Valve lodged in the strainer of the turbine throttle valve. Figure 1 page 8 of Reference 1 shows the detaDs of the internal components of the W K M parallel expanding gate valve and defines the nomenclature used in this report. Basically this is a wedge gate valve design in which two wedge pieces (called the gate and segment) are employed wh;ch expand in a lateral direction. During the mid travel position, the lever lock shoe (part of the "leverlock" cam assembly between the gate and segment) is guided between the gate guide rail and the segment rail which prevents any relative axial motion between gate and segment thereby preventing any tendency for the two pieces to expend.
LP&L performed comprehensive investigations, analyses, tests, and evaluations in order to determine the scope of the problem, root cause, corrective actions and safety implications.
This report provides a synopsis of these actions.
Scope of Problem LP&L determined that both main steam isolation valves were affected by the failure mechanisms. An inspection of MSIV (MS 1248) showed that both gate guide rails had separated from their seat skirt. One rail had been broken into two pieces and these pieces were the ones found in the turbine throttle valve strainer. The second gate side guide rail to O the same seat skirt was severely bent and was found inside the MSIV valve body cavity below Q the gate. The two segment guide rails on the opposite seat (segment side) were still attached
, to the seat skirts, but several of the bolt heads were found broken. The guide rails on the other MSIV (MS 124A) remained attached to the skirt but several of the bolts on both guide assemblies were broken. There were vcrying degrees of galling found on the top and bottom of the Lev R-Loc arm shoes and the guide rail chamfers where contact had been made.
There was no other damage to the MS 124A Internals. The main steam piping was visually inspected, and there was no visible damage to the ploing other than minor scratches and gouges. MS 1248 had shallow gouges !n the body, presumably caused by the broken rail.
There was no damage to any other plant components or systems.
Analysis Various analyses and tests were performed under the direction of LP&L by Kalsi Engineering.
Cooper Industries, and Materials Evaluation Laboratory, Inc. These analyses and tests included:
. Transient Dynamic impact Analysis During Gate Closing Action, see Reference 1, Appendtx A.
Appendix A presents a simplified math model of the Mc>lV which was used to determine the root cause of the failure and to verify the performance of the new design.
v 7
MSIV Guide Rail Fallure (cont.) June 20,1988 O
. Upper Bound Estimate of Loads Transmitted to Guide Rails, see Reference 1, Appendix B.
Appendix B presents several upper bound load calculations.
These calculations show a maximum impact load of approximately 103,000 lb. on each rau (assuming a valve closing time of 1.6 seconds). This impact force can't shear the bolts if the loads are equally distributed among the bolts, but will if the load is triangularly distributed.
. Analysis of Forces and Stresses During Gate Opening Action, see Reference 1, Appendix C.
Appendix C calculations demonstrated that under high frictional conditions associated with galled surfaces the maximum load on the segment rail when the valve is opening (coupled with triangular bolt loading) is capable of shearing off the bolts.
. Bolt Shear Stress Test, see Reference 2, Appendix B.
This appendix presents the load / deformation curve for a new unloaded screw and a screw removed from the segment skirt f]
V assembly. This data was used in WKMs impact analysis calculations.
Lev R-Loc Shoes and Gate Side Seat Skirt Guide Rail Impact Analysis, see Reference 2, Appendix C.
WKMs analysis shows a load of 429 kips (brick wall analysis) with galling,15.1 kips with no galling and a 45' chamfer on the rails (original design) and 5.5 kips with no galling and a 30* chamfer on each rah (new design).
. Metallurigical Analysis of Bolts Fastening Guide Rails w,ui Skirt Plate, see Reference 2, Appendix F.
This metallurigical report shows that failure was 6;e to a combination of factors, including shear, corrosion and
)
Induced stress on the bolts. This report recommended that the bolts be of the same material as the rails and seat skirt (17 4PH). l Bolt Stress Misalignment Analysis, see Reference 2, Appendix E. {
This appendix presents alignment data between the skirt and rail. Maximum misalignment was .0342 max and the '
corresponding stress intensities were 234 KSI. l O t l
l 2
l MSIV Guide Rail Failure (cont.) June 20,1988 l
D (Q . Metallurigical Evaluation of the broken guide rau assembly with screws using photomicrography, scanning electron microscopy, optical metallography, j
l hardness test, and chemical posttion, see Reference 3. l This evaluation was done prior to disassembly of the valves !
and it concluded that the major failure mode was shear l overload. A follow up evaluation after disassembly of MSIV's ]
was done and some severe corrosion pitting was found.
l l
Root Cause The root cause of the MSIV gate guide rah failure was material galling caused by the localized j geometry (sharp edges and 45' chamfer on the rails) of the contact surfaces of the Lev-R-Loc l shoe and guide rail chamfer. The galling and shoe / guide rail contact geometry resulted in l excessive friction which developed in high forces being applied to the guide raus and transmitted to the bolts fastening the guide rails to the skirt plates. The corrosion pits on the ,
roots of the threads served as crack initiation sites. The impact loads combined with the l Induced stress on the screws caused the cracks to propagate and eventually some of the more heavHy loaded screws failed (heads popped off). The results of the scanning microscopy and optical microscopy Indicated that the ultimate failure mode of the remaining l bolts was shear overload. ;
gs The following factors contributed to the failure of the bolts. '
. Misalignment of the bolts fastening the guide rails to the skirt plates, see ,
Reference 2, Appendix E.
i
. Corrosion of the bolts fastening the guide rails to the skirt plates, see Reference 2, Appendix F and Reference 3. 1 C'.>rrective Action !
A number of design enhancements and corrective actions have been implemented. These design enhancements and corrective actions will provide assurance that the gulde raus will not be susceptible to the same failure mechanisms. Reference 1 page 13 shows that for a closing time of 1 second and using a high coefficient of friction the modified design has a safety margin ratio of 8.
The design enhancements and corrective actions are the following:
Changing the contact angle on the guide rails from 45 degrees to 30 degrees. This change dramatically changes the maximum impact force on the guide rail from about 31 kips to about 5 kips for a coefficient of friction of about 0.67. (See Reference 1, page 11) 3
MSIV Guide Rail Fallure (cont.) June 20,1988 l i
. Stelliting the contact angles on the guide raus and the circumference of the Lev-R-Loc shoes with a Stellite 6 overtay and smoothly merging flat surfaces with 5/8 inch radil. This change will prevent galling of the Lev-R-Loc shoe and guide ral! Interface.
. Changing the material for the bolts fastening the guide rails to the skirt plate to 17-4PH. This change will prevent galvanic type corrosion of the bolts due :
to material incompatibility between the bolts and the guide raus. In addition, the 17-4PH material is more corrosion resistant.
. Performing NDE for all new bolts. This preventative measure wal provide assurance that the bolts have no surface flaws. I
. Verifying clignment of the bolts fastening the guide rails and skirt plates. This preventative measure will assure that stresses are not generated from '
misalignment of the bolts.
. Verifying the proper torquing of the bolts. This preventative measure will assure that the bolts are not overstressed due to over torquing. I NOTE: A question was raised on the type of lubricant used in the assembly of the skirt assembly. It was determined that LPS-3 was used and is j an acceptable lubricant for this service. i
. Gouges (in MS 124B and the pipe) were ground out and all dimensions !
O verified to be within minimum wall thickness. I b
In addition to these changes LPSL did a preliminary evaluation on increasing the valve ;
closure time, i.e., having the valve close slower. Preliminary evaluations suggest that this may not be feasible, additional evaluation is required and may be pursued at a later date.
LP&L Intends to perform inspection on these valves during future outages utilizing a fiber ;
optic camera and recorder. <
l Safety Implications The important considerations from a safety standpoint are to provide assurance that:
The valves will close within three seconds.
A loose guide rail or Guide rail piece will not prevent the MSIVs from closing.
(see Reference 1, pages 1517).
. The loose part generated from a broken guide rail will not affect the safe operation of Waterford 3.
Appendix D of Reference 1 includes details of various worst-case conditions and their effect on operability as well as closing times The conclusions are:
O .
Fauure of the gate side rails has no affect on the closing time with flow in the normal or reverse direction. This was the as-found condition of MS 1248.
4
1 MSIV Guide Rail Failure (cont.) June 20,1988 O t dr lon s has no affect on the closing time wfth flow in l
. Failure of the segment side ral could increar Sosing time with flow in the ,
reverse direction (approximately 1 second \ i an expected coefficient of i irletion of 0.2 to .25). Falure of the segment snje rals has been included for !
completeness, although this condition was not found in either valve. Failure of the segment raus could be postulated if the valve's condition had continued uncorrected.
I I
l l
l 0
S-
l MSIV Guide Rail Failure (cont.) June 20,1988 i
REFERENCES r
- 1. Kalsi Engineering, Inc., Report, titled "Preliminary Root Cause Analysis of i MSIV Gate Guide FaDure," dated May 9,1988. ;
- 2. i Flow Control Report, titled "Component Falute Analysis and Design Enhancement Report," dated May 6,1988.
3a. LP&USSI, Report titled "Preliminary investigation of Broken Guide j
Rai Assembly of MSIV 1248,"dated May 20,1988. .
3b. Material Evaluation Laboratory, Inc., Report, titled "Metallurgical Examination of Flat-Head, Socket-Drive Low Alloy Steel Screws, ;
Contract #C30752," dated May 11,1988. I O
O
.s j
ac:
I LOUl81ANA P OW E R & LIG H T / INTER-OFFICE COAAESPONOENCE MRaIK1 Q May 20, 1988 W3B88-0659 ,
A4.07 '
QA j TO: N. S. Carns !
t FROM: J. R. McGaha
)
SUBJECT:
MSIV Guide tail Failure ATTACHMENTS: (1) WKM Failure Analysis and Design Enhancement Report (2) Kalsi Preliminary Root Cause Analysis (3) LP&L/SSI Preliminary Investigation Nuclear Operations Engineering provided engineering support and coordination to Paul Backes in determining root cause and corrective action for the subject failure. The following support se rvices were utilized in conducting the associated evaluations:
1.
O WKM, the valve manufacturer, performed a component failure analysis and design enhancement study. A final WKM component failure analysis and design enhancement report is attached.
2.
Kalsi Engineering, Inc. was contracted to perform an engineering technical evaluation of the root cause and a worst case safety analysis for MSIV operability with failed guide rails. Kalsi's ,
preliminary root cause analysis (Document No.1560 C) is attached. {
(Final design verified report is expected by May 27, 1988.)
- 3. LP&L/SSI engineers performed a materist evaluation of the failed parts which also included an evaluation of the cap screws which did not fail. The preliminary results of this investigation are attached. (The final report is expected by May 27, 1988).
The root cause of the failure can be attributed to a combination of engineering, fabrication and material deficiencies as summarised below:
- 1. Valve design resulted in excessive galling of the shoes which significantly increased the forces transmitted to valve internals, j especially the rails and cap screws, during opening and closure cycle. (See Attachment 1, page 4 -
Item 9, Attachment 2, page 11 and Attachment 3,Section III.)
l "AN EQUAL OPP 0ffrUNITY EMPLOYER"
W3888-0659 Page 2 of 2 May 20, 1988 2.
Pre-existing cracks in the cap screws may have contributed to O cap screw failure. (See Attachment 1 page 4, Attachment 2 page 15 Section 3.3.)
3.
Cap screw corrosion may have contributed to cap screw failure.
(See Attachment 1, Appendix F page 2 Attachment 3, Swetion IIIc.)
Items 2 through 5, and 4
Rail and skirt misalignment during fabrication resulted in uneven distribution E.) of increased forces. (See Attachment 1, Appendix l
The correceive action as discussed in the WKM report consisted of the following design changes and improved fabrication techniques:
- 1. Changing the angle on the rails '
- 2. !
Ste111 ting the angle on the rails
- 3. Changing the angle on the shoes !
- 4. Ste111 ting the angle on the shoes
- 5. Changing bolt asterial to 17-4PE for rail bolts
- 6. NDE all new bolts !
l
- 7. Verification of alignment !
The design changes listed above have been promulgated via DC-3037.
l The final Kalsi report including the worst case safety analysis report i and the 1,P6d,/SSI report should be completed by 5/27/88.
J. R. McCcha JRM/AP/enj Attachments cc: D. T. i igk, A. Pastor, Records Center, Administrative Support, ,
i O .
i
Page l of 54 O '
ROOT CAUSE ANALYSIS OF l MSIV GATE GUIDE FAILURE 1
l DOCUMENT NO.1560C REVISION 1 i l
JUNE 10,1988 l
l Prepared for l
LOUISIANA POWEP. & LIGHT COMPANY WATERFORD SES UNIT 3 !
KILLONA, LOUISIANA s i Prepared by Reviewed by i
. N. b v i J. K. Wang, PhD, P.E. M. S. Kalsi, PhD, P.E.
Approved by l
KEI m No. 40.4 I c>- d.
Todd Horst Quality Assurance t
k B_
}~
i O
KALBI E NGIN E E RING, INC.
vt O = ANCa* C E S-GN f. A N A.
- S S
Document No.1560C June 10,1988 Revision 1 Page 2 of 54 O
TABLE OF CONTENTS Page
- 1. INTRODUCTION 4
- 2. DESCRIPTION OF W K M GATE AND SEGhfENT ASSEhiBLY PARALLEL EXPANDING OPERATION 7
- 3. SUhiMARY OF RESULTS AND CONCLUSIONS 10 3.1. Valve Closing Action 10 3.2. Valve Opening Action 14 3.3. Other Factors: Material Defects, Corrosion, Misalignment 14 3.4. Worst Case Safety Analysis: Operability with Failed Guide Rails 15 3.5. Overall Conclusions 17 REFERENCES 18 APPENDIX A Transient Dynamic Impact Anaiysis During Gate Closing Action 22 APPENDIX B: Upper Bound Estimate of Loads Transmitted to the Guide Rails 30 APPENDIX C: Analysis of Forces and Stresses During Gate Opening Action 5 APPENDIX D: Analysis of MSIV Operability During Closing with Guide Rails Broken 46 O
KALBI E NGIN EERING, INC.
v e :-as e., c e a s. <. .s.. .. .
Document No.1560C June 10,1988 Revision 1 Page 3 of 54 j t
l '
LIST OF FIGURES l r
No. Page
?
i t
1 Nomer.clature of Components Used in W K M MSIV Gate Valve 8 2 Comparing Impact Forces on Gate Rail for the Old and New Guide De signs 11 l
- 3. Time History Impact Force Plot for New and Old Rail Designs 12 i
l l
i i
o !
i i
I i
1 l
1 KALSI ENGIN EERING, IN C.
vec-* sci.crecss.s.....
l Document No.1560C June 10,1988 Revision 1 Page 4 of 54 1
- 1. INTRODUCTION This report summarizes the results of the root cause analysis completed on the Main Steam Isolation Valve (MSIV) gate guide failure that occurred at Louisiana Power & Light Company's Waterford SES Unit 3. These main steam isolation valves are designed and manufactured by W K M Product Division of Cooper Industries. The basic design consists of a through conduit, parallel expanding gate valve of 40" x 30" x 40" size which can provide the wedging action in the closed as well as the open position. Figure 1 shows the details of the internal components and the associated nomenclature. In addition, a description of W K M gate and segment assembly operation and its wedging / expanding action in the open and closed position is given in Section 2 immediately following the introduction. For I a better understanding of the root cause analysis, it is essential to read that description.
The failure of the guide rails occurred sometime since the plant began its operation and April 1988 when two broken guide rail piees:! were found in a strainer downstream of the MSIV. The MSIV was disassembled and inspected to assist in determining the root cause of the failure. The failed parts were shipped to W.K-M and inspected by personnel from
. Louisiana Power & Light, W K M, and Kalsi Engineering. W K M Report ER 7834 documents the observations made from the failed parts as well as the condition of the other internals. In addition to the broken guide rail pieces that were found downstream of this MSIV, it was observed that all the bolts holding the other guide rail to the same seat skirt on l
the other side of the valve port had also sheared off. That guide rail was found inside the valve body below the gate. This guide rail was found in a bent condition, apparently as a result of the force applied to it by the gate. Both guide rails that sheared off were from the wat skirt on the gate side (Figure 1). The two guide rails on the opposite seat (segment side) were still attached to their seat skirt. Several of the bolt heads were complete y severed from the bolts. Severe galling was found at the top and bottom sides of both shoes as well as on the guide rails. Galling was apparently initiated at locations on the shoes which have initial contact with the guide as the shoe approaches it from either closed or open position. The other MSIV was also disassembled and inspected. The damage found in this valve was reported by LP&L to be similar to the first one even though it had not progressed to as severe a condition and the guide rail bolts had not sheared off. l l
O KALSI ENGIN EERING, INC.
-=_.s=.=....~.....
l l
l
Document No.1560C June 10,1988 Revision 1 Page 5 of 54 Kalsi Engineering, Inc. was engaged by LP&L to perform a detailed review of the failed and damap4 parts to determine the root cause of the failure. A mathematical model which simulates the impact forces and motions of the gate and segment assembly during closing action wo developed to conduct the review. This model takes into account the velocity of the shoe at impact, th= coefficient of friction between the guide rail and the shoe, the local contact geometry which includes the chamfer angle at the top of the guide rail and the attitude angle that the shoe can acquire within the clevis of the lever lock arm. An upper bound calculation was also made to determine the maximum force that can be transmitted from the guide rcil to the shoe when galling becomes so severe that there is no resultant torque on the lever lock arm to guide it or force it toward the desirad central position between the guide rails.
An important variable needed to perform the root cause analysis was the actual velocity of the shoe before it hits the guide rail. The MSIV is closed by the stored energy of the gas spring which also forces the hydraulic fluid on the lower side of the piston out to the sump when the valve is closed. The velocity time history of the gate and segment assembly was obtained by a simulation program deva!oped by P. D. Alvarez of Kalsi Engineering (KEI O Report No.1523). This program takes into account the nitrogen charge pressure at the top of the piston actuator, the hydraulic pressure below the piston, the weight of the gate and segment, the hydraulic resistanco of the manifold and piping system through which the hydraulic fluid is dumped during the fast closing action. The original program was developed to predict valve / actuator closing times with no pressure or new through the MSIV, and has been found to correlate well with actual test times. This program war me 4fied to simulate valve closing times with flow through the valve. This was accomplished by adding a frictional resistance term caused by differential pressure across the gate, which was conservatively assumed to vary linearly as the gate travels from fully open to fully closed position. Comparisons against fluid dynamic forces due to impingement against the gate using drag coefficients show that the above assumption is quite conservative.
To complete the root cause analysis, several material tests and dimansional inspections were performed by W.K M as well as LP&L. The purpose of the material tests on the bolts was to ascertain the actual mechanical and metallurgical properties of the materials and determine any potential material defects, service corrosion, or initial daws that might also be responsible for the observed failures., The dimensional inspections included a critical O KAL51 ENGINEERING, INC.
=-ave .ee.cse..s o..
Documenc No.1560C June 10,1988 Revision 1 Page 6 of 54
' G review of the uniformity of the speing between the bolt holes in the guide skirt and their alignment with respect to the holes in the guide rails. The objective of this inspection was to determine the potential nonuniformity ofload distribution between vtrious bolts that hold the guide rails to the skirt. The material testing and dimensional inspections were performed by W K hi and the iesults are available in W K hi Report ER 7834.
In addition to performing the root cause analysis on the present design, this report includes a review of the design modification in the guide rail / shoe geometry which was proposed by W K hi. The same mathematical model which was used in the root cause analysis was employt3 to determine the magnitude ofimprovement achieved by the proposed changes. A compariNn of the results from these two geometries including the sensitivity of the results to the ve.mtions in coefTicient of frictien is presented in this report which shows the advantages of the proposed changes as well as their relative tolerance te high friction and some potential galling that could occur during operation.
From a safety standpoint another analysis was performed which specifically addressed the T ' significance of no guide rails in the valve on the operability of the htSIV to perform its safety function. A failed lever loen mechanism can allow the gate and segment to expand laterally against their respective seats and increase the frictional forces opposing the motion of the gate. Whether or not broken guide rails affect the closing time or operability of the valve depends upon the flow direction and which guide rails have failed. Analysis was performed to determine the ability of the actuator to fully close the valve as well as the increased closing time under the various postulated conditions.
This report summarizes the results from all of the above analyses,i.e.:
+ Root ecuse anclysis of the gate guide failure;
- Analysis of the modified design; and
- Safety analysis considering that the guide rails have failed. I l
The important conclusions from these analyses are summarized first which are followed by detailed calculations in the supporting appendices.
l l
O l V' KALSI ENGIN EERING, INC.
w.- ~ . : sos 6 .s.. . . s l
I
Document No.1560C June 10,1988 Revision 1 Page 7 of 54
- 2. DESCRIPTION OF W.K M GATE AND SEGMENT ASSEMDLY PARALLEL EXPANDING OPERATION Figure 1 shows the details of the internal components of the W K M parallel expanding gate valve and the nomenclature used in this report. Basically this valve is a wedge gate valve design in which two wedge pieces are employed which expand in a lateral direction whenever relative axial motion (in the direction of the stem) is allowed to occur between them. This design relies upon the two pieces to travel together as an assembly without any relative axial motion (or lateral expansion) during the entire stroke except at the very ends when the assembly approaches the fully open or fully closed position. To keep the two wedge pieces called "gate" and "segment" from moving relative to each other, a special mechanism is employed which provides the necessary kinematic restraint to the entire assembly. This mechanism is comprised of a "lever lock" assembly, which consists of a lever lock arm, a lever lock shoe, a cam assembly between the gate and segment, and guide rails which are fastened to a seat skirt on each seat. During the mid traval position, the lever lock shoe is guided between the guide rails which prevents any relative axial motion between gate and segment thereby preventing any tendency for the two pieces to expand
. laterally which can result in an increase in the force required to move the assembly.
The guida rails are terminated at either end of the stroke of this valve to permit the lever lock shot to move outside the parallel restraint provided between the guide rails. When going toward the fully open position, this in turn permits the gate to continue to move upwards after the segment hits the bottom of the bonnet which stops the upward movement of the segment. This relative motion between the gate and segment is transmitted through a special cam mechanism (not visible in this sketch) through the lever lock arm which kicks j
the shoe to the left as shown in Figure 1. This allows a wedging / climbing action between the
{
gate and segment to take place which is accompanied by an increase in the dimension i between the parallel faces of the gate and segment.
During normal valve operation, when the valve is given a signal to go closed, the gate and segment assembly starts to move down with the shoe stillin the left position until it hits the top of the guidt rail (as shown in Figure 1). In the current design, there is a 45 degree I chamfer provided at this location of the guide rail which tends to guide, or force, the shoe from this extreme left position to a central position between the guide rails. It should be KALSI ENGINEERING, INC.
ve:-.*:..=ascse..s.....
l
Document No.1560C June 10,1988 Revision 1 Page 8 of 54 O :
pg m.. . ~.,~. ..,~.. ,~..
esse a mvse comeAtars :
J - I C
4 %
.; \ . i a ,
PA %
r r- p)., .
/
1 l
5 l
kZ [B -
s-( y SEGMENT STOP
- o,. SEGMENT ;
e]) / LEVER LOCK ARM P
gg LEVER LOCK SHOE ,
g yf LEVER LOCK ASSEMBLY' w s4h% WW7 ~
w GUIDE RAll '
l' , - GUIDE RA!L SKIRT .'
GUIDE RAll ASSEMBLY
/
SHOE HlT HERE , e---- NORMAL FLOW WHILE CLOSING d
( ,
SHOE HIT HERE s 6 WHILE OPENING 2 ')
FIGURE 1 NOMENCLATURE OF COMPONENTS USED IN WKM MSIV GATE VALVE KAL51 ENGINEERING, INC.
l l
l
- - , - - - - - - - - - - - - - - - - - - ' - ~ ~ ~ ' ~ - ' ' ' ' ~ ~ ~
1 l
l Document No.1560C June 10,1988 Revision 1 Page 9 of 54 l l
I l
noted that the edges of the 45 degree chamfer on the guide rails are relatively sharp with no significant radii. These are potential sites for initiating galling. The gate and segment assembly travels together through the entire stroke until at the very end when the segment-stop hits the stop pad provided in the body upstream conduit. After the segment motion is stopped and the gate continues to be pushed down by the stem, the relative motion between the gate and segment now engages the other set of inclined planes and starts the wedging i action. This is accompanied by a motion of the lever lock arm and the shoe assembly which l is kicked to the right in the closed position In the fully closed position, both the gate and the stem wedge pieces are laterally expanded to firmly contact their respective seats and provide the desired seating force.
O O KALSI ENQ1N EERING, I NC.
vee-*s.c.,ce css ~.....
l 1
i Document No.1560C June 10,1988 Revision 1 Page 10 of 54 i l
- 3. SUhDIARY OF RESULTS AND CONCLUSIONS 3.1. Valve Closing Action (1) The root cause of the MSIV gate guide failure is concluded to be due to material galling and the localized geometry of the contact surfaces of the lever lock shoeiguide rail 1
chamfer that create a very high impact load while attempting to guide or force the shoe between the rail. The top and bottom surfaces of the shoe that contact the guide rail were found to be not overlaid with hard. surfacing material (Stellite 6) which had been !
used on the radiused part of the shoe. This absence of overlay material and lack of i radius at the ends of 45 degree chamfer in the guide rail, caused high contact stresses and severe deterioration of the impacting surfaces, eventually resulting in galling.
1 A mathematical model capable of simulating the dynamic impact action of the ;
assembly was developed to analyze the root cause of failure. The details are included l in Appendix A. This model was used to simulate the geometry of the current guide rail assembly (45 degree chamfer) and investigate the sensitivity of the results of the impact force ganerated to coefficient of friction. The results from the mathematical O model show tha;in the present design, as this interface deteriorates and the coefficient of friction between the shoe and the guide rail increases from a normal range of about 0.2 to 0.4 to values of 0.6 or higher, there is an asymptotic rise in the magnitude of the irnpact force delivered to the guide rails (see Figures 2 and 3). Theeretically, as the !
l coefficient of friction reaches a magnitude of 0.72 for this 45 degree rail geometry, no i torque is generated at the shoe to guide rail contact to cause rotation of the lever lock arm and force it between the guide rails. Under this condition, all of the kinetic energy of the moving gate assembly is absorbed by the load resisting components and converted into strain energy. When this occurs, the magnitude of the forces transmitted to the guide rail becomes very high, and can easily cause shearing of the l guide rail to skirt bolting as observed in the failed valve.
I It should be pointed out that coefficient of friction of 0.72 is in the possible range of what !
l could be encountered when the two surfaces are galled, as found in the failed guide rails and shoes.
l l
l I
i 4
KALBI E NGINEERING, INC.
.e-.sc.. m e.s .s... u
O O O 1 X WO y D g
> r" d- c I 8 2. B
'; - g-
- , a <- r" p E
~
l GATE VHDC/rf = 2S I*Ysee b h Ie h 544r wf' = 2500/4 I 1 1= y m
g ,
I On
~ ~
N k<
m.
2 <(
g .'
. t 2 y ** ~
K
.n
~
5 : >
T r
"46* RAIL A%lE LESKM og
? (a9trrs#) E-oa se i2 5 io -
l 30* RAIL AW6LE MSMM hy (NEW DE316N) OR h i u 2o -
p .E i 22 1
s 5e-1 Z eo -
ff E 5
p _ =r/.22 (3* Jes19-)
m = 0.72 (e s*desrgn }
o . . . ~=. . . ,
o 0.E e4 c. 4 r8 f. O r. 2 s. 4 *ts G
- 5 9m COEFT/C/EN T OF_ FRICT/04 n"_8 oe F/G. 2 CDMPM/A/6 AMPACTftsfrF5 04 t9 ATE RAIL FOR THE OLD AMD A/ER/ Gritnr Mst&n s $ww i
I
Document No.1560C Jun310,1988 Revision 1 Page 12 of 54 i
K ALBI ENGIN EERING. INC.
C(l'Oh & ANALYS15 CONSULTANTS Cut'Dufa*aeste, saSt No t Catt 6 Sat.10' 9'
,s' '
,s'
,.- ~
/ %
k s's t 4
,s' & ,
/ 1 x
/ '
{
/
s' %
o
^
i q
/ o %
/ b t "
$ e
/ ' $ $ k g p w' '
/ /
2
% U k !
O l I
{L sl de ~;9 !'
g s
MN ti D 4 ) $ a s .t. e..
Dk
, :s 3, on !
, ,s o- :
N N
d 4, f Eg i
.(%
-
- g-g N / '
s u
- w gz/ , =n s k7
's #
h[
d 's #
"E
$--4
's * '
s{- EQ s 4 ne Ns k NI N
- n 'N '
k L
- s. s ..
R 5
%y ' '; 50 st 4* 'e t e at .
zo
, e i g RD N $ D & "
- m J/N ' 7t YU NO BMGe' M t'dW/ .
O KALBI ENGINEERING, INC.
va:-.~c =aac.ss s.....
Document No.1560C June 10,1988 Revision 1 Page 13 of 54 i
O i b ,
(2) To estimate the upper bound values for the impact loads delivered in the current design, five different approaches were used. These approaches, described in Appendix B, included the use of available impact energy, maximum actuator static !
pressure, and the strength of the failed and unfalled components in the load path. The estimated range of maximum impact load delivered to the guide rail is approximately 100 kips for each rail. This can cause failure of the bolts between the guide rails and ;
skirt.
(3) Figures 2 and 3 show the effect of changing the guide rail angle from 45 degrees to the ,
proposed new design of 30 degrees. The results show a dramatic reduction in the magnitude of impact force delivered to the guide rails as the chamfer angle is i changed to 30 degrees. The results clearly show the relative insensitivity of the new design to coefficient of friction increase until magnitudes reach unreasonably high values in the range of 1.22, which are much higher than can be encountered in practice. It should also be pointed out that the surfaces of the shoe which previously were not overlaid with Stellite 6 have been overlaid in the new design and the 30-degree chamfer is smoothly merged into the flat surfaces by generous 5/8. inch radii.
This should prevent galling damage to the shoe / guide rail interface. I l
The magnitude of the forces transmitted to the new guide rail under a relatively high choice of coefficient of friction that can possibly exist in such an assembly is found to be below 6,000 pounds for the valve closing time of1.6 seconds. Even with the valve I closing time changed from 1.6 seconds to 1.0 second, the maximum impact force is still below 10,000 pounds (n = 1.0). Based upon the maximum impact load of10,000 pounds, the safety margin of the rail load carrying capacity to the rail load is eight time s. As shown in Figure 2, for the normal impact load of appru'.mately 4,000 pounds (n = 0.3), the safety margin of the rail load carrying capacity to rail input load is as high as 20 times.
(4) As shown in Kalsi Engineering Report No.1523, Actuator Closing Times, the impact load analysis in this report is based upon the fastest valve closing time of approximately 1.6 seconds (or, more specifically, the gate assembly speed of 25 in/sec KALSI E NGIN EE RING, INC, )'
vi:- s ca. ::e nos s * ..o e a l 1
Document No.1560C June 10.1988 Revision 1 P ge 14 of 54 O
before impact). The impact load estimation would vary significantly with a different closing time or gate speed.
Valve closing time is a critical factor in the gate guide failure. It not only affects the magnitude of the impact load, but can also cause the initiation of surface galling, as observed on the rail chamfers and the back angle of the gate assembly. Therefore, slowing down the closing time within an acceptable range for the plant operation should be considered. The more commonly used MSIV closing time is in the range of three to six seconds. A quantitative comparison of the impact forces for various closing times can be provided by using the transient dynamic impact model described in Appendix A in conjunction with the actuator closing time simulation program described in Appendix B,if required.
3.2. Valve Opening Action As shown in Appendix C calculations, the valve actuator has sufficient hydraulic force (660 l
kips net ) to pull the gate assembly upward, if the resistance exists due to the shoe and rail I
'sticki n g.
High coefficient of friction between the shoe and rail causes a high contact load on the segment rail. The contact area from the MSIV layout shows that the shoe touches the rail at the lower corner of the chamfer, which resulted in surface galling and tearing, as shown in the actual hardware. The maximum contact load transmitted to the segment rails is estimated to be about 84 kips per rail.
High closing impact loads might have caused deterioration of the gate and segment back angle, resulting in a wedged gate and segment assembly moving up together during valve opening. Under this condition, high forces can be transmitted to the aegment guide rails during valve opening action.
3.3. Other Factors: Material Defecta, Corrosion, Mina11rnment Although the analysis shows that the root cause of the gate guide failure is due to the excessive galling of the shoe and rail chamfer surfaces, other causes such as corrosion, low ductibility, and pre-existing cracks . could be contributing factors to the guide failure.
O KALSI ENGIN#1 RING, INC.
ve:- sca.: -sss. s..... -
Document No.15600 June 10,1988 Revision 1 Page 15 of 54 O
V The results from W K M's material test show that the ultimate failure of all the bolts examined was due to fracture by shear and all the bolti examined expressed some metal loss in the form of pitting corrosion.
W K M's bolt shear test also indicated that the old bolt (used in the MSIV) strength is approximately 76 percent of the new bolt strength. Some corrosion and pre existing cracks were found in the old bolt, which may have weakened the bolt strength. The shear elongations are 0.0925 inch and 0.127 inch for the old and new bol's . respectively.
The hole alignment measurements (as given in the W K M report) show that the maximum misalignment is 0.0342 inch, but the majority of the bolt holes have much less misalignment than the maximum value.
From these test and measurement results, it is concluded that the root cause of the rail failure is due to the shear overload. Corrosion and misalignment may have contributed to the failure.
O 3.4. Worst Case Safety Analysis: Opembility with Failed Guide Rails Appendix D includes analysis details of various worst case conditions that can be postulated regarding guide rail failures and their effect on operability as well as closing times. The overall conclusions from this analysis are:
1 (1) With Gow in the normal direction, the failure of the gate side guide rails has na affut i on operability, and closing times will be the same as in a healthy valve.
(2) Predictably, the closing times with flow are 0.3 seconds higher than closing times during tests run with no Dow.
(3) The failure of gate side guide rails and segment rails also has no effect on the operability and closing times with Row in the normal direction.
(4) With Cow in the revuse direction, the failure of gate side guide rails has no effect on operability and closing times as compared to a healthy valve, a KALBI ENGINEERING, INC.
ve :- s.:.. en ;,s s, as.. . s .
Document No.1560C Juns 10,1988 Revision 1 Pau l6 of 54 i O i (5) The only condition under which operability and closing times are atfected is with flow in reverse direction and segment side rails failed. This is the worst case !
condition from the standpoint of safety with postulated guide rail failures. Even under the postulated worst case condition of steam line break (increased flow rate of 6,000 lb/see and pressure of 789 psi), with an expected range of 0.2 to 0.25 coefficient of I friction, the gate is predicted to close with an increase in closing time of approximately 1.0 seconds. Analysis shows, however, that an increase in coefficient of friction may prevent the gate from fully closing under this worst. ease scenario.
(
l t
It should be pointed out that the failure of segment side guide rails is highly unlikely l because it sees very little load during normal operation; it acts when the gate is I unwedged from the closed position. The travel velocity during this operation is low; I therefore, no significant impset load is applied. The unwedging force, discussed in
{
Appendix C, is very small under the normal operation (without galling) and should i not cause the segment rail failure. The major di#erers a in the MSIV segment side f
guide rail and the conventional segment side guide railis the absence of a radius that
[
initiated galling in the MSIV. The conventional design (with radius) has been used in W K M wedge gate valves for many years of industrial service without any
)
l reported failures. Therefore, using this proven design feature in the modified MSIV l rails should prevent any future failure of the segment rails. I I
r (6) The effect of the failed guide rails on the valve closing may be evaluated in two ways: j (1) Rails in the Valve Body Cavity: After shearing off from the gate skirt, the !
failing rails are moving downward with the gate assembly. The r6!1s, <
without firm support from the body cavity, are more likely to be pushed aside or bent in the confined space inside the body without affecting the closing time of the gate.
A broken guide rail can resist the gate downward motion ifit is oriented virtually at the bottom of the body cavity. Since a falling guide rail will hit the curved spherical surface of the bottom ef the body cavity, it is improbable that a guide rail will remain vertical in the valve body.
O KALBI ENGINEERING, INC.
v: =-* .c . :s em s .s., ae
l Document No.1560C June 10,1988 Revision 1 Page 17 of 54 O Therefore, we believe it is highly unlikely that a guide rail in the body cavity would stop gate movement.
[2] Rails Bouncing to the Flow Stream: The failed rails could bounce to the gate opening (conduit) due to the valve closing impacts and steam flow in the valve body. Under the worst postulated case, the broken or bent rails could stay at the edge of the seats to prevent the gate from a complete closing. Although the chance of this situation happening is difUcult to quantify, it is believed to be extremely small.
3.5. Overall Conclusions Our thorough analysis has identified the cause of failure to be galling of the guide rails and shoes. The modifications that have been incorporated cure the root cause of the problem. A review of the modifications also shows no new problems are introduced. The valve would have performed its function in the as.found condition.
O O KALSI ENGINEERING, INC.
v i : -.~.e .. = . o ~ r. .~. . >.
l Document No.1560C June 10,1988 Revision 1 Page 18 of 54
- css l
- 1. From Friction and Wear of Materials by E. Rabinowicz, John Wiley & Sons,1965,
- 2. Travel vs. Time and Total Exiting Flow Rate !
- 3. Louisiana Light & Power Bolt Analysis, Direct Shear Test of.508" Bolt i
l O
l O KALSI ENGIN EERING, INC.
vic .- c., ca sos s as.. . .
Document No.1560C June 10,1988 Revision 1 Page 19 of 54 I O REFERENCE 1 i
Friction and Wear of Materials by E. Rabinowicz I by E. Rabinowicz John Wiley & Sons,1965 i
l l
1 l
6 i i i ty 0.6 -
k -
im
\~ O
\
f N Iubne,
~
O _
755 lubncated pm iuencated by a sono
' i i i 10-3 10-3 10-' 1 10 100
- v. em/see Fig. 4.45. Experimental friction-velocity curves for stul on steel, unlubriested and perfectly lubricated by a soap, slao derived cun es for intermediate stages of lubrication. "
O KALSI ENGINEERING. INC. ,
l
- -.s c., c a s o s i. .. . . .
- , - - - - - - - - - - - - - - - - - - - - - - - ' - --l
Document No.15600 Jure 10,1988 R3 vision 1 Page 20 0f 54 O
REFERENCE 2 TRAVEL VER3US TIME AND TOTAL EXITINC FI M RATE TOTAL PISTON TRAVEL . . . . . . . . . . . . . . . . . . . . . . . . . . . 31. 25 0 VALVE INTDBAL PRE 3 $URI . . . . . . . . . . . . . . . . . . . . . . . 10 8 5.0 MITROCEN FR135URE (CFEN FOSITION) . . . . . . . . . . . . . . 2073.0 FYRQUEL 150 TEMFDATURI. D ECRIES F . . . . . . . . . . . . . 5 FY1 QUEL 150 VEICHT DD311Y (L85/CV81C F00T). ... 73.98 FYRQUEL 150 VISCO31TT (CENT!!ToltF.5) ........... 5000.0 NUKB ER OF HYDRAULIC EXITS . . . . . . . . . . . . . . . . . . . . . . 1 SArt cleting he = /, 4 Cu.
- NOKpCLAtv11 ***
L1 - FISTON FOSITION FROM FV110F5 TIME = ELAPSED TIME DUR.!NC TRAVEL Q = TOTAL FLW RATE PRISS.TQF = NITR0CEN FRLS5URE ASOVE THE FIST 0ft FR133.50T = HYDRUALIC FIRID PR135VRE BE1M THE FIST 0sl F. FORCE = NITROC D PR135URE FORCE
- 1. FORCE = TOTAL 81313TANCE FORCE O
L1 TIME Q PRESS.TCP FR138.50T P. FORCE 1.FOR0E INCHES SEC CFM Ps!C FSIC LES LAS "
O.00 0.000 2956.8 2073.0 2056.4 937803. 937703.
0.20 0.008 2943.9 2055.0 2038.3 929680 929580 0.40 0.015 2931.2 2037.3 2020.5 0.60 921675. 921575.
0.023 2918.7 2019.9 2003.0 913784.
0.80 0.031 913688 2906.2 2002.7 1985.7 906013.
1.00 0.039 2893.9 905913.
1985.8 1968.6 898354 494254 1.20 0.047 2881.7 1969.1 1951.4 890801. 890701.
1.40 0.055 2869.7 1952.6 1935.2 883357 883257 1.60 0.063 2857.7 1936.4 1918.9 876019, 1.80 0.071 2845.9 875919.
1920.4 1902.8 868781. 868681.
2.00 0.079 2834.2 1904.7 1886.9 2.20 861648. 861548, 0.087 2822.6 1889.1 1871.3 2.40 854612. 854512.
0.095 2811.1 1873.8 1855.8 847672.
2.60 0.103 2799.7 847572.
1858.6 1840.6 840828. 840728.
2.80 0.111 2788.5 1643.7 1825.6 834078 833978.
3.00 0.119 2777.3 1829.0 1810.8 3.20 827420. 427320.
0.128 2766.3 1814.5 17S&.2 820832, 3.40 0.136 2755.3 820752.
1800.2 1781.7 814373. 814273 3.60 0.144 2744.5 1786.0 1767.5 807978. 807878 3.80 0.153 2733.8 1772.1 4.00 1753.5 401670. 401570 0.161 2723.1 1758.3 1739.6 795447 4.20 0.169 795347, 2712.6 1744.7 1726.0 789301.
4.40 0.178 2702.1 789201.
1731.3 1712.5 783240. 783140.
VelecIhg beAre impa4p, _2.C. 2.u , , , ;,,
d /#J.e *t5' #
x ALs eNo Nassi No. Nc.
m - - . ~
KALBt ENGINEERING. INC.
- -. .s e a w. s. . .. . s s
l Document No.1560C June 10,1988 ,
Revision 1 Page 21 of 54 l
o REFERENCE 3 l l
l l
l LOUSIANA L&P BOLT ANALYSIS '
OIRECT SHEAR TEST OF .505" BOLT 0.17 0.1 6 -
i i
0.15 - '
0.14 - l O.13 -
0.12 - 'hv 6 V.tll AC LY , .STR bVTED . . _ . . . i p 0.11 -
l C' o,1 - -
2
@ 0.09 - /
0.05 -
O 0.07 -
0.06 - #9 -
o '
0 05 - .
8-0 04 - 2 !
. . _ . g 0 2- #' -
fa
- i,7.M M \1 ii 0.01 - -
v1 '
y %) '
O ,,
O 3000 6000 9000 12000 15000 18000 21000 :
r SHE#t LOAD (LES) !
O N M M LT + OW MLT I i
O KAL51 ENGINEERING, INC, va -..c..einoss.s.....
M
NI ENGINEERING, INC.
Document No.1560C, Revision 1 ,
Jm 10,1988 i Appendix A Page 22 of 54 !
l l
I l
i l
APPENDIX A l TRANSIENT DYNAMIC IMPACT ANALYSIS DURING GATE CLOSING ACTION f
i f
I l
i l
1 l
KAl.El ENGIN E ERING, INC.
ve:- vc..=enoss.~.,...
K.t! SI ENGINEERING, INC.
Document No.15600, Revision 1 June 10,1988 Appendix A Page 23 of 54 l KAL.sl ENGIN EEMING. INC. t 06848 & AasA&Ytl CCHSLATAWS Custoute emesset AApfND/y A saat wo 4 ./ j Dave
%eSJtC' 'nn> A a f 2 MM *Y* O YA!A M H* TM 9AJ*.'1' AMALY_f Lt 9' Dut!MA ? A '*f t f ? T/ WS A? *rn +.'
In erder k kk.e in+e oecouny the signil'iau + 4.s.fws 1
. . . l
- which afee.t +4e closing inpact /os.d , a si,np/;fisd m*H1 atodel was
~ Nieweirpei65se)[rf,e e/csinf mechanism, relarise stianass ,
L anel toras assump + lam.s. 7% e 119o t fies..t oQsk2 , thot .. u
\
~ ~
Air'e5 ~fhe closing impast /hde aru SAe in.il'onh/c (chams'e&
\
~
roeMicient of frie.ficm da ring de trnpac.f, Va/re closing speeck '
.5ehm'l4Oe~i91 e 5,~A',5 le'v~k ~5ec 5llgenNeNy ~1,,2 5 KeAti'.?
75e'14lios..ny o/skar?~m5Si5m1sl 00sh/* As A *INIsV l the e/ostng impa.ct Sa_ _ . .m the insHal cerhet c4 /Ae shoe s-Jrsil 1 l
. _ _ . _ . . . . _ . . . . . . . ... . . . . . yA e e,.sta.s i/ j
+it/ + heir setaestien . It pro videt.M n* wasj h an*4f 3*)es<.
'~~
. Tiepsifica,e Ac/vra a.sd tAstr perfrem ersee rasy as . 7h e ,
resuHs . .. of. '/ti.s o eenQis sNUbe ab/s fe $s/p us,. ralenti&. tfA
- __ . . . . . . . . s u. . .
Prof care of this guide, fa.ifure and peri /sf fire perdemsnee
'~ ~ ~ " ~~ ~
. ...Tc~{ the'~'p&se['eee.s a5.~9n .' ~ .
..f. Clousoy Empaet 4,al y 4.
Durins ohe earlsg valve closing, rMe Ankm r/fAe LA-loc TAee
. . ormk.h . . . ._ .. . . .
._., fAe en.i/ Cham /sr . The re su/w.r en Acfirm forc< frrm +6e.
.. rail (sormally provides a. necessy t% pus k push fire.
.. Lev-R Lee ossembl., to the coes,sse of the p,ds rsu'/s. 7"A rs
'^_ N>eeA s eum is da.c icy n ad t. p Nve + g ah M rapm 9 s r n ed ,,,g
_ . da ring atosia sg . . . . _ ...... ._ . .. . .. .. . . . . -
KALB1 E NGIN EERING. INC.
vi:- sc*.en.csn..sa. ..
i
ICALSI ENGINEERING, INC.
Document No.1560C, Revision 1 June 10,1988 Appendix A Page 24 of 54 K ALSI ENGINEERING, INC.
04544% 6 ANALYSIS con 6atANis CysteusepaesgCt anos No J .2 Datt
~ ~
'. TAe 5:2ng tmpest anElysas is e/Yelep ad h ca/ss./sha Ne
%ns;em' impace /en.d. using in ersmeorral fitne afsps k
~
N. sienss/Je t/re nny sedien fr tm in I+ist t.en M ie Ano3h.
~~
.- . he s e , &y a s . s.J a < utsu2C .u/As su d.vJapad 4a s ed'
. m some sonop/ fieJ sosumphcess 4 pnviele a resere*Ur.
the of f}e ns AM modsf .-
- he~Niledn~fSse ~v~e N~s' assuky~tuv s are used in deudaptk I
?.-- t/se instf mods /c -. .._ .. ..
' ~ ~ ~ ~ ~
' 1) le vi Lee NAh~t5e Alg }/$r~b/o iNwndor andu ne .?
Q.
^
d
~55s~dN.e r pared wiU50~ody gde 6 m ms-4 ~ .'
c~pum rs). J/ Adelo+<'r ,J .f/ss;61/dsj extsh in tds.-
~ ~ ~
~- :- os55Lly ;.lIw5/ m$1s 5eiijs%n seHse anJ tfre
.a,p a.d /n d k w sr.
?--... D Qak u.J seg ms.a aass<n sty n elt af a censkt spted
?'. ~. Aehre *,J Q .da impe;flead.C ss= leu a very ht9A
~ '~
~
\
impu.h /ssAl oes.u rs , the cle>Ing 5 speed wit / her :
. - - - - be e tg n i fies ely %e .l /w th e ass .ph m ).
_ ._.-.--. 310 Ssy mut u eiy A r a d ep,,,9ti , At ased ir. rA e Lee-A-Le c. . .
. - - . - . sr , a.eEsieeat t'm eJe~.lc.L.,s. . 7Ae la v-R.t.e
~ ~ ?T ~AN Q &54 ta rsk%<l; s ns.l/ sem.psAsd shE4.
. th e s sys s r % M, is rug Isa./ << .
(
O KALSI E NGIN EERING, INC.
vie-*ve. ceeoss.s.....
KA1.S! ENGINEERING, INC,. '
Document No.1560C, Revision 1 June 10,1988 Appendix A Page 25 of 54 t
8 KALei ENGINEERING, INC.
- Ottack & Aasatvl48 C044ATAssig evstouta*eest:* anot No ) . 3
=_ Datt lvest ? S' The impad samdJJm au phed ky 6e fol/wany s%s s_
1
._ l} CJest a rmall f;ee rtsa. _
it) C.Je.JJ< th., dose, & haael e,,/ /s& de ffeda'n . .A
.. in) C,Jed ;te M /wes emens h > reswlos.J M, ad .._.
. kque due h t/rts aMsd travela *(a's//ea4rn . .. .._
.___iD CJa.Jste. due aceslustor ., ,.ucle st% .o ad da r/sems t of - !
. Me rep ,s.. _ . .._ ..__ _ _ . . . . _ . . _ .
~
i
~_ _ _.r 6 Q i T/s ; 4 .<e gu a, 6e % 4., G . M d r
- f. A aw* Ame r%p. . . _ _ . . _ . . _ _ _ _ _ _
q .._ _ . . . _ . . . . . _ _ . . . . _ . _.. . ._ _ :_ ..
. 2 &9 u rtvm 6 the Impa d Ass,,is i
~
/bt bl/sm, liny M&flr tonstics( ef sssfirns erg ._.d eeing ) A,y Hre _. '
_ _.sN p4.6# e7P'ue/sJN rr,4.' . . _ _ _ . . . . . . . _ _ _ . . . . . . . . . . _ . I
_ .5) &* A*deC AtM... .90.l0mlb s /.' &
i
. b The lev-R.Las arar //eattath t.s cote.s/s.t / dasa r e.,
rte /.//w;9 S; pfdi<.d m s.e4 m dst. . .. .. ._.
P5,
- _A ,
Oe/hdw .f.f ser
-_ .rf g 7
_{ (f%3 wAece J = J2. t " ..
p . . .
- 21. F /_.17_8 J.$ g
. - . _ _ . . .. .... . . . . J .
. . . .. . .._..... _ . . . _ . /1
. - _..._De4ledin.4.s24xtop*. . . _ _ .
KALBl E NGIN E ERING, I NC.
vi:-.s c.. c e s as s .s.. .. .
KALSI ENGINEERING, INC.
Document No.1560C, Revision 1 June 10,1988 Appendix A Page 26 of 54 KAL51 EN GINEEptlNG, INC.
ens,ou *>.aosis co*swa=ts evs' cues eso.,get emot wo A.4 Catt susa:,
e-
.- n) ket& and Isted s.splace.ne rts at de e mMt charnM. ._
.a y . V , a t 3
...._ %*j",4' .. -..w k we V - closing valeen , nAas. .. :
' ~
sg -
.ct a rt-,e .,.ces w , s u.. '_ .~. .
. _ . .4=A69 . .
wAwe o = cle m le f!Il. Arce and fm u e n /. firm s .... . .. .. .. . . . . . .
Lat<<a/ A,< e ine n m en t 4r a pve n . ---
r 4 '~. ** 4 , ....--. . . ... . . . . ..... . . . . .
(
. == la!*WAl d&CCh'en inCrt**eosf i ..
a6 fy~ as
. i d . . . _ . .. . Ye $2 Y Ale . - . .
--~s .
S*l SS b tM1AA S CS **ntrtniemT . .
I. h. 'b p r, --
....J Cr ..
~
a_ fn m .
- - - . .. . . . . $6 3 $ ..
-h l '& \ Y .
. .. A p. - . . . . . - - _ . . . .-.
.Fu Ts .. .. ..
...kAt wHs os t St a be t t'en s em & 5 ..
- .% 9 .-.- . ..
.g d&
y , 3. up3 . ..
. _ - - - . . . - . . . Wb 0ft pr Ces[.Of A,chers af
. n t Cond Sk r$s sa .
Nrvr)en* A!!F% plis fm.asC 6 , d
.-. .Cl en f.,o .1t*% $L ELgSi*e(f*0*Nh*Oh t
.. .. .. ~ _ ._._
KAL51 ENGIN EERING. INC.
,e : ..s .. e a sos 6 .s.. .. .
KALSI ENGINEERING, INC.
Document No.15600, Revision 1 June 10,1988 Appendix A Page 27 of 54
\
K AL51 ENGINEERING, INC. i 1
04&48:4 Amygr8 CosukAJamts '
Custeesea esosect emot see J.S Daft S ussGC T ST
_-- Verflead dup /sesoveser At Lev.A*.l.ec nem! Ogv 4 y 'titue k Inters?
o afrDretsm psG 4[m S gy a J s3 4x .
i
.. .. .. . . . . 4J J 2. r 1%yue htCet men T o 4 7"eq ue
.. A Te,que an A Q ol
. . . . . . ~ . . .. ... .
. . . . . _ . . . 1
_ _ ~ _ Set in Ctsm **W AY' C4 **.o. Af y, . __ . . . .
- .n Tevq.- - - . . - - . . .
s . 1st ue . - - . .
. /-2 . . __ i
- . . ._ 1 ACc*l*ftWen $5Credseest44v fat 39 m ent . . . . . .
.,g*
2 Ae4 =.
d oet .nt an segmeert nuest a 2toofug,y
-._ _~Sesmenr..vertre.<l alap/sesmeer ,414 t.4,enmaw .- .. .
~~
A y ' = M at +. .f. o, .st' - - . _ _ _ - . _ .
- . .hbse e ..Ve a b Viessa jtersmrit,s $ k's/cg)G, o%/u . . . . . _ .
....._A..
. ... e* -)*_te. W. .een.s ./ tentlon's eeg e/o est.je . l */p.*
- _ _ ~ . . . . . . _ _ . . . . . ,. . . . . . .
. .. _ Sej m em + V6YfitAl VelesiG g/p , e .j dry s t jopgrq m g,g ._
V = . V. .* a e t . .. --. . .- ..
.l./nelefksfed ax movement du e h sy'moveme.r, s.x' 4X's .IJ '2 d [ as . 22* . .f .a * . _ .
J. d 3 4
KALSI ENGINEERING. INC.
. -. c a ce no . s . .. . . .
i
t KALSI ENGINEERING, INC.
Document No.15600, Revision 1 June 10,19SS Appendix A Page 28 of 54 i
KALSI ENGINEERING. INC. !
Otl+0's & A8sAusd4 ComesATAarts cv5'0wie **Csget !
esSt teo A .$ i CA't
, < ..t e, ,
D= dane shove dertN'dr~slatiresAlpsDAe5mse.T ;
~ ,
~ ~
'. -.- 5%sli of SNut so(Nifias Esh.n ca easily be pednA sd -
l, 45ing a fMTtAW ce,&w p.g- - . Tbe resdts ef Ast: . . . . . . !
(
% e ses p'ett d tu thown in l4' t.1 s d. .k .
.. . Ag . . Z 24n.ra the oml/ trend of th e Le v.4 las assemb/p _ i l
performance as fanchens of /de cloam4w a gh a d the ...-.. l,
- . ~ ~~c~oedc'le~~f.~o[~Nis~+5.: ^i ~
t 7h 4t a A /* tcPr*'*nt Yhe Af0*'.i5 l.
.wAtle +ks so'onsle is the new sAs.,,4w eles:q a. R x4. o/d e'asin .
, l
-- as +4e conftcio r of Aostie,
.. i
.% pea a.t Art.< .. I
- _ ' . . . . . . . ..n erss>ss th e
.. . . . . . . _ . . . . i
-s% c ruses ' sAw._..f.;. J A esi-
.. . 7Ae in,,p.st ha fck4 p elely d+w the co*6tur-r o/ $ eh m..sw cada c . G . . Zt 1
~ - '
i~dii4a am xisu ~.~efch M ,,o
% 4s ..
geeed.ad u,.de rAis Aip caeficie.,r of &c.1-im. 41 tA:s .-
~
~ - p'o5t tie 5 A.~.a'f & 3 '4ae.i. ts.4ey d csp J,hnj offb
- ~ind n.Jst M caja.sJa.i.] z/ c- A .4 a.<ri,,J d ss l
..-. . Gwn in ' Apps , dix 8.) . Mm. & fr.s.,d cle. .J., sAms ..
i
- -- Sa.t., Aq A impast h ees.we s//w t/se coeficieer of
. (!
..-. . fr.'e.b m *u.esds o. C ola .e fe 14 e f.u+ da a.yp w cas p h,ym I As Neis 5 t:r%c.L.-yperkshes_ fat lev-A lse sa,.scis (ddo).
?~$~A SY{ e aIe., beel tsser%es , tat coeWo ctost of fr.dtr,s
- is eatImedsd tu ie 6 c. 2. M. o, a & 5 % t.J. !). F E. ;
fsilad n se. The ceefiet.o.taf fr?e.5n~ S hu[e5 ~5y&
O l U KAL51 ENGINEERING, INC.
v t O aN Ca. O E SGN 4. ANA.
- S 6
KALSI ENGINEERING, INC.
Document No.1560C, Revision 1 Jttne 10,1988 Appendix A Page 29 of 54
(
KALBI ENGINEERING, INC.
Cts 4N & A%4?las CON 64AJANts CVl? cute *eOJget angt wo J. 7 CATE s . s . . -,
e,
+A<.
- c. 6_wido A an oj 'p rvAlem. _7be..~fe_ s _.. . she at odinat.yas e.,n rs. f ,~.jt4..ss~,deneu .
... _ .-.e 4 p r o s.d ss, ks e s o,, the rh e s ud ra.1/ c/r a , A. o , / tis 3 ce, Judsd rAar Aigh imps.st Arca. 1s. .rAe nest /iist.- y __ l
. . ._ j.n. _ _ . . . . . _ _ ... . . . . _ _ .
-. . roof cua. r$ xt's W,%Lewi,,y va4e cheny .
~
_.~ . 5%e. p s vn',s,hf af i~s5~Sec. sei~setev.ismea'r,, AC.:
~
Eshs~ia,e~a.,,,, & Lp.Je cy.. irk *4A.a - et aiGG.'
__. a s 84am _ir, A 4 < ,ca._J.. .__
... _ 5, rA
- ne<s) du a t*
- the !"Y Aca $ . _. .ce re mains ve
rde cos4cie.,r af f..afre ,
Ar,~~ reig y *fM npsa. tad darys. -
- R$. B. SAews the rhme his,4,y ef .tfe i,,,pe.g.f fwce s $ t4<
- - DM s.d mes~o & destyt. On 94scoeWien q cf Mt.rm c%
6vm _o c..2. e 47, p.4., e(d r
.e.,% 4 s ,4., Atu
.:7 . .
.- -.- 1% s~.U 2L m ? %a , pm.n. i s M L f M .
KALEI ENGINEERING. INC.
vi:-. ..c.. ei so . 6 . ... . s
_ _ , _ . . _ . _ _ _ _ - ._ ----- -.--- ----- -- ----- f
t k
KALSI ENGINEERING, INC.
Document No 1560C, Revision 1 Appendix B June 10,1988 Page 30 of 54 1
i t
i I
I f
1 I
I i
l i
i APPENDIX B l i
UPPER BOUND ESTIMATE OF LOADS TRANSMITTED O
4 4
j 1
KALSI E NGIN E ERING, INC.
vi:-.s.: .=esass s...s.
KALS1 ENGINEERING, INC.
Document No.1560C, Revision 1 Appendix B June 10,1988 Page 31 of 54 ;
i O
l K AL51 EN GIN EE RING, INC.
04:4= a amatvsis cowswtaae ts !
,,cyssowna*eosee' A PPCA/D/2 A esoe no 81
?
oave sve AC* /JpyBd* D?tJA.!B~R1**1A e A rm 821 BAT) t 9EAVTMf s t nu t' i
._... _.- _ . . _ _ _ . . . . . . . .. .. _ . . . . . t
. Several uppae bound h sd calcda haru taill be , =k sd .
._.in. rArs ype dix to es tima.h r'/reinaxiinum knpa.ct /osd
. _ _ _ . _ _ . . _ . . l
. .. betoy 9p /, ed r'o tA e ,4 iled yat.< in /s . Ertime.hns caill. . _ . . . _
.. se based en +1,e a vst/aue .an e y cou rc< , f rsaare , A;/ed
_ mans, ts ,. gstled runkes , a.s ws. ../l a- t. _ .un do m y sd ... . ._ .. '
Wo n Me.t we in tA s knpaa.t /. 4. pan.. Simp /did maa m ods/ aJ s ssm hrns ar e ne she J 6 puh these. . . . . {
e<pm hou A cJe.u.b% ... ._. . .
. .L Lising de Avails 1/e /finefic Energy As Impast-Load ist'ime.rir, l Q
A s ss ~ n in f d u g. ......_ l
. _ b 4 fv*'t im
._......y. av t y A ~>e~ip
- ?'h e s u ras e,p a.t,,t .
ts t3 hm shs.d Vo b e 3 L~ #"l14s (A* ICssc efeting itme),
,- {
YCon diti.rn s en ih t !b o s & iLtud in dies /4.s'avwe
- s. fid/q 9 . . _ _ . . . . . . . .-. r f :,,WRA durIng M~ft Cleting . {,,lneles" Ysts byh frie llrm coal, '
t esi& . . 8 t. /*tCss ha n t $, t t m s=1 P&
d P9y 4 8 /74 L8y=,f. 4d a h11 A//M 5 Lh M*sn Arm . . . . . . . . - . _ . _ .
{
.M8 ~
% us g en er%#sd / 4a e myac/*
{
bff 4.4f $ e Grtspere a.f,
. h.
,SJ mA/e/ h !
u5,1Ae gah asss nity sk,ec !
.ta;/ % e tho* su n,sn I 4e.e
, l 5*'"**rk~dl*7 s&ppsal & fle N ,
l ~ Assulk..t s~rres . ' gds 5is . 7A e i, ,p mag na hd , l iw w l mes a . _.- __._.__... ... . . _ - - .
..Cm 64 et+Irna tsat y eq u.s. tin g ..
1 I
l l
O' KALSI ENGIN EERING, INC.
i 8atO v
4% Ca. OtSO N4e e'.ek%%I i i
i i
1 i
KA1,SI ENGINEERING, INC.
Document No.1560C, Revision 1 June 10,1988 Appendix B Page 32 of 54 l
1 K ALSI ENt31 NEE 141NG. INC.
C45:44 & A8e ALYS18 CONSW.TANTS l
cuttewes**estet esog ne 82, Ca't Swt.Get 8'
d e m ov n g. . .. .--:.<mws' knek e.ne.4 y h d e sh u .-.* sy-y .
. - _ of .He /oJ my.ng compens.Js . The A//owing r+4 ness est:mehen s Y Y.. firr Yle5$t= 1ny 5 ee11tds Ars /WlWmest 14115e o'mh f
f*
. A e. .. . . . . . . .s. ad m.1J ...-. _.
_/
Nineres sierpy = si m v
- _
.. . l v Jh,nt,,e,ysy= y r Q
- ._ t >. <. __. .. .. _
./ . _ _ _.
.- g. _ . . - - _ _ . .
g . . . . - . _
- . . . . . _ - Ja.s.a .
.. .- t
.- - . -. . . .**-f m v ' .. _.=. }. s'Conw. (nejled.ng the he.phr Q ) . .
... - _ .. . y p , ..in y n.
..._.-_...g . _ . . . - _ _ _ . . . . . . . I
. _. .._.. 14 *rs .tr, a ff 3g /4 (nM inoesay samp.,s.ce) ......
set.s. . _- ._ . . . . . , . . . _
yq f ,,g . _ __ . . _.
.-- -. j
. f/x , g. MJ tttfaea , t%,, '
F e V /m # .. .
- w%ere k ca., se eshmaad as :
)
. l} lt * *h le t a rm SWa tts (on e Ar on ) _.
. .... g p , As , /.treas 3 ,,.7 s _/. t tr t. r,3,,e 7 : .
. . . dt. L
.. . . . ... . //. L ..
3, 9 7 ,,, 7 fg . ._ .
KALEI ENGINEERING. INC. i vi:: .. .c.. : s a c.,s r. *s.o a s 1
i
KALS! ENGINEERING, INC.
Document No.15600, Revision 1 June 10,1988 Appendix B Page 33 of 54 x
KAL58 ENGIN58ERINGs INC.
04548e & A44vl:8 A*MwfANT3 Cus toi,s e isost Ct emot wo A.3 ca?t S v e . t CT ST ii). Carl MtKness (me ent).) _ . . . -. . - - _
4nme an a Wedeve /e,,ytt */ /d st/>e fehJ /e,,pk ._
. _. . . . . h'z - M9 r !. rt S * ' = /.e r4 x1o Uy;,, . . _
_ 12. tX e. D 313
. =. . . .
- _. _ .lin delt shfne u for,e rail.)
(See /s/srence 3 of the belt shearing fest resuth ) _ - _ _
~$s 5]I*T*' A~5lt, nt /% - sing /e~ It '
.?' .
- 0 e .- - _ . . . . . - . _ . . . . . . - - - . - _.-
~
. . . K.s a 9a Aa m 2 84 xio ' W.n .c' f b ens ) - - - - . .--
~
h5]NO ~e5e,rJ<S~.rhMnes s .1,4r hoM sia'as ) ' .... ..-
- /
._ ._-N a ,,
, # /
a 4. 3 5 3 r so # ///., .. --
._ - . . . . . . .t Ko .2h ars . . . .
r - 2s Tin w .n u,,i ,'T,.;.,',u a- '~
4 m.u . . . _ .
7*bY LYL$ikEbIa 6tke o / es fim im,fl1e m%hssam L . D -7 2 % < a aos, n n W y d< d u:n , s/ > r s e. .
~~~ K L.,, s , e s dw,y r,,,,e
/.< u.>. _. . _ . . _ . ;
4/ sing the Sra tte 4% Pr*ss ure L Impe 404 d'.utim
. 2
. .P rm kEfuse,ce a N e & p m su re at 2. 6 .., fre va !
~
is 1 4 vs.6 p ' n. 909 h ! 14 ef 4s.d. .ZE tie CAe e i
~
t%sts em .the ra1h .cl,5es . ds<.s he~5's'Th eNA E5 '.
l l
KAL51 E N GIN E ERING, IN C.
m...c..~.......
i i
__, ,,_ _ . . _ _ _ _ _ . . . - - - - - - - - . - - = = -
1 KALSI ENGINEERING, INC.
Document No.1560C, Revisien 1 June 10,1988 Appendix B Page 34 of 54 s
KA L51 ENGINEERING, INC.
015804 4Ahagy$t$ CONSWTANf 3 Custouga neestet neog No d.4 Sgt.t0T OATE OF anoU$e' ~55y5frw$s50?5e GeMN 5N$
is, 1- ]EN tbe ne$ drND 5ee oNAr rui/ h e.stris,s.h.d5:
c~
. . o m = ? 40,/2 7 Ack.h Rshn arss (/Ss9n), ..-
Dck.o : Adcis,p Dy ut N3 ), i ..
Wv< Ask:q Dm.g c r, H 9)* -.
.- bn.1sksa es.t mse (n, 6s s )*
+ Moviruj Wc t-( dj2 41)*
- 4. NG":
W (No./$2L Warr J./ Jl . "Dame No'Q C4A y;-j fra Ja n e 19,19t 7.
s-. ",
.. Fue.t :*. 791>043 14. .
7At. is tAe twent assum ed lesh rf sr mAny Mannh. . . . .
f~
( _in. . tie /ea pati my A.iL &n, m%se c<./m/ anum , .
it' / 4 Concludd tW +his ca,,dsttm didnot cem. .
- 3 Usi-j the Sheer Strs.96 at the Rai/ Charnfar 62. met /.osed [st.
. . .s. . . . .
Auum e . 6t is vertrua.l'
l , .
\
Assume tAe shear shw.s c.t the
-- j g '
..-... of g . . m& surAu e4 rlsN 4 tha sheae .
, O'r**f/4. . _ . . . . . . _
/ 7**of (n.il/CA*e a a.6tnr, **a psi ( Gsr4 nQ
~
- . p, ,\%.f ~ ~ = ?C ooo ps1
__ ]_^.[ '/ ' ' ' Ft " TurY A m
- - - - -@ . . = 7s, n o A h > o.6 3 S A /. it s'nter
' ' ~
s)
._.. . - =_74, r?814...
- - - - -- l- Fg = dT x 7 ti,rfa /b = fo r, as9/b .
KALSl ENGIN EE RING, INC.
w:- s.ca :n sos s. .s .,s e
i i
KALSI ENGIh'EERING, INC. I Document No.1560C, Revision 1 June 10,1988 Appendix B Page 35 of 54 KALSI ENGIN EERING, INC. -
CE5 ION 4 ANALYSa5 CONSultawTs t evsteusa *=esset anos wo B-6 DATI .
su.a:,
a- !
. __ . [
- 4. Unny de An /. _ _ __._... .An Hole stronp'A A< Impur Locad Eshm.fim xd 3
,, . Arm.. ,
?. .' , .. .f. 5 is VerhCAl . . o -.
.- ...... i
- 2. . s n 2 a.s % ~ rheat ( s = o. n .
~:-_y~-6
- h. a,+Gta,y m s 2 a e n i^h'
. .! [4 Cet Jg.i s [g, '
. .. - - .-.frem He aboWL estumptreu, fy w f e .. l edim cJe.4 a s s . . . . . . _ . - . . -
.Y
) -
- M' a
.p
. 3 " se SA - S
. . cnza. i .n
".T_-
l l
5t - . . . . - . .. . .
= 0. r38 4 % . .. l
. ..Ib s4ere ,Me pin ; c%b 7sx:;)
.. .. .. i
_ . . - pp = R,p Aw.'. . . . . .- . . . .
- . = 17 s>ooo / la I'x 2.
. 88./1 7,.P/ O /6
. . - . . - . . - . .<. 5 = m ,rto , 2,g,y,g t$ _ ^ ' . _ _ _ _ _ _
.. . - _. .f. r.$ 85/ .
- -- / . .-
To shev 6e inn A /s :.C% s.7cka ) .__. . .
fg a ns,ooox/x(c. m 4) g _
t g*L {
. . . .. = lor,ooo /L
- Q = 3o o>. r4 4 /J
% 1 1
KALSI ENGINEERING, INC. 1 vi :-* s c... c e s w, r. ..,<.. . s s
KALSI ENGINEERING, INC.
Document No.15600, Revision 1 June 10,19S8 Appendix B Page 36 of 54 K AL.El ENGINEERING, INC.
oesca a awvsis conswawts CUSTCuta pec tCT eact e.o 8.f Svt.tCT Catt O'
^
~
..S.. Osinhie~N.Te~)rAb)l% ~Zmh.e,+ Lu.4 Zs+1me.fiav,
. Assum* s -
.. 4 ,, f
.. r. ..... A a's v e m ! .. .
.. .A 4 A
~
. .. / N
. . _ . . _. (
. ..Sech A-4 = /. 75i 3. 315 " '. ..~.
.g .. .. .
Mans ers t e & B4 . . .
.......9
-- . 8 encl,'ng W'8 ..
5'"' . g
.Cg'~ a :n j, 2.0 y y
. . . . . . . . ../* 1G I'Y T , _..
~ ' ~ ~
~~
~
............ /2 _ . . . . . .
. . . - .Auw;&~No e'in5/m ur>,
qdtfe
? .
= __.... - -.. . _._ s ,*u sta n , a;,,,i., i.e ry , s , .
J. Tx /oo,co e = /. Lo y Pa'
-- . -. . ._. .- . . . . . . .: 5,e = 124,rtc' u...
C. CottAbear $4rna Ca/cJat/ms .
--N sed on the eleve s dih~h'ns, t/se ir,c,xi,roun, i ,jout-
. - - Josd in tk gafe nail i.s est, mated .h so m,6s4 ti, e ca d,
. .. . . mil. 7Ae _ shear shws n ese4 4*tt ea- 6e ast,mM
..in f%/0 9 4424?
. .... I) AvetG$ t s A ta./ ft'rtt L
~ ~ ~ ~
- - T 4.ve'l '/ o i , 'L4 L = fd,L(% y. < **to t WS! Cst. TAesr %k
.- - .. - _. tJ.3*L . ..
. . . . . . . . < $de L ks 1 7a' t7ul ** #o
- - - . rhes'e . tat eve + Mas a c. u 1 ,*,,'
f., $f 41 vas . _ .
KAl.Sl ENGIN EERING, INC.
- .* E 0 AN 0a Og S.GN r. AN A.
- 5.S
KALSI ENGINEERING, INC.
Document No.1560C, Revision 1 June 10,1988 D Appendix B Page 37 of 54 ,
1 1
K ALSI ENGIN EERING, INC.
CI5JON 4 ANALYSIS CONSUL
- Nets I
CVstewga eacsget pact 40 87 OAft 565st07 SV l l
. . - . ~ . .
The Jolt sAest strw9th (4]P , Re s.ta ) is estim+tsd as . - l rry.= l sox 0. 4 = 4 o iai . ... .
. . . - . . . . . . % =/7024.6= /o1 kJi . .. . . . . .-
. . . Frem the WKA chese fest CRe.4,* ,ee 3) . --
. . . ' .~~~? Tca t+ = I o , y, z'i; g , _ _ _ _ _ _ _ _ _ . ._ _ _ _ _ _f.
1
... .-..ii) Tria ng ulu sAear losa datri burim . .....-
- ' 1
,# o y - fi e /02,141 1 0 the* M , ' . , 3 2, y , 7 ,g , _ .. . _ _ _
{
, . . (t+ 7 + g + 4 /* 0 ) . -
- . ~ .
- . 9 5, , , ...0fa _2173[ 4. 'LD L m jl2, 449 f fa.sE > /010'45 & M
. . . . . . . . . > OA. L h I & hast
~ ~ ~
.74e A5we e+/en/afImD5' ~s 5:2 th e e,shmM movimw n
~
- imy$5ee.Al5n~NoITEw .S[Ndfs if /od 'ts erEdir ~ ~
hesir,%tef amen 3 +4s S/W ~.'f;C5e~52 5~5?a;g~u~Cth l dash;LJul a.: shun in the 4ee.eAsf cs/a.dslim, f' )w YAe o'm & /a su:l en 4 i/ fke' beHs . 7Ae un egu.a./ /vad
~ ' ~
5 -.. Nt'ssktdufim Ehosst6 le dae /o 74e relafiye sftffness l
~
o / tat /oc.d ec , eying'~me$Q~/oD ;krfitutim s, ide" ~
.alif n me -+t , and stru5 ^Adwa.c.fim s.
A!H.4 de,tri impur to:i:{ /s tAe mest h4ely roo+ eme r} fhe g 5+e E ll k u /are ' dUthN / AcJn s suc.4 s.s s torrattwefeJ,.lawee tiem e,wgeet boit steer,9kb cofue f, e n su <&t.n emela s . ek ) n fes.) rdae tr/, +u u sa. . . . . . .n,+ s e .
KALSI ENGINEERING,INE
...c :- s :.. :: e s .s s .s.. . s i.
KALSI ENGINEERING, INC.
Document No.1560C, Revision 1 June 10,1988 I_ Appendix B Page 38 of 54 KALSI ENCBINEERING, INC.
OtSJGN & ANALYSi8 CCMSULTANTS Custoute peostet asog so [d Oatt iv.a e, m/ut ed. with.a a non44 m cJws/ fsdin$ . 74erek..
. . _ . a Atluce in sole in veshpJtm av +Ae Anksn hoffe shu/of
.. . _ . __ .. d e & vt. . .Invadtptium of 1%e tw),nken ho /fs es _
_. ds o recom_ .n&d 4. the wplete u.,nters%2neling of .... ...
1
_ .. _. .__-fAe r_o *__ _+w.. . _ . . . _ _. . . . . _ _ . _ . . _ .
{
_ . . . __. . _ . . . I i
I i
. _ . _ . . . _ . . _ . . . . .. k I
l i
-. _ _ . ._______ = . _ _ _ _ . _ . _ _ . _ , . i
_ i l
i 1
I i
KALSI ENGIN EERING, INC.
(
l ..:...........s.... .
KALSI ENGINEERING, INC.
Document No.15600, Revision 1 June 10,1988 Appendix C Page 39 of 54 APPENDIX C ANALYSIS OF FORCES AND STRESSES DURING GATE OPENING ACTION O
O KALSI E NGIN EERING, INC.
w :- sc . ::a scs s *s.... .
___ ,__ _ . - . , - - - - - - - - - - , - ~ ~ ~ - ~ ' ' ' ~ ' " ' ~ " ' ' ~ ~ " ~ ' ' ' ' ~ ~ ' ~ ~ '
l i
I i
KALS! ENGINEERING, INC.
Document No.1560C Map 5, M68 Appendix C l
Page 40 of 54 L
KALBt ENGINEERINCB,INC.
CES4N & AneALY$18 CONSULTANT $
CusstuthMCJt *T A P94A"lo/x e e.oe **o e-/
C.T5
%Ys.5C' AWAL Y.11.1 8 C Ke9 t'C.t Astb 211?At tA-f dud 12 t3 tG'b '9'& 8 9 PA21 M G A f9 % Al es
/ .Va/ve Opening /iwce 61timwim ..._. ...._. .
Du etng eafe apening ,.2f e gale spee.d a s/ew.. There& e 1
. . .. on .. . . . .
f tbe /mdf ,e seg m em rut /s cm b e frde d tu et stuti:. /oa.d'.
~ ~
.. i Ae awila4/* $ce km de Ayitsd5c. prubuOeX,4' [:-~
6s hm 44 ad 41 a
. fn s9. m _. .. ..
. . _ . . . _ . . ' .hisd up we.td hse . - . .
..= Hy4seda &c.< .M' W Ma
. . . ~ Acha+/w th 05
~.Ac%te, Adun y Drs.g . .- . .. . -- ..
-- Valve Psakiy Dm9
. . . . . . . .... --Movan g Comp M tef. _ .
.x Mooe e. 79se (w'- 4') - 12 4y a e. ?rtye .34 ' . . . . _ .
. ....._ . .... .. ..-- / s,'9 sz .. ..
.. .. . - - . . . . . . -t2,te3 ..
~h - f,u9 (V ... ..
. _ = (t.), 2 70. /A .
- f. Iw
. _ 7bt ..Are, the ock.M cu prwde ruR:cient A. ee fa ove rcen e ne s
- _ . . . . . . ee ms.4 rail remianes (s),ewiq Me Joh) 4 Me shes ..
._..' d ^*',dMr $$a sA fofeMw. . ..
_ 2. E fa<.t.of Bie.tbe,st Carf.'etents ... ~ ' ~ ~~ ~
. Oaeing va/ve opeoing ...Me stem puHs tAe ye p4 L ..
. s/ou sp<ed. Z/ de ):<.tk dr~eg ne t are s/m- =t,.
. s'n .
- a. ullap sed posit /m . rk d e lov-R.Loe m t,.iin v%
[etNac~ A M 1/'y--M Ms,/.4.,ae r/ 9rii // ca T
' ~.:.55 /r,eiQmid'rie u[m%. n.t/s. Z/ Aspede ~
.__* n ct s9 m e.d rumin tandjed dwing oput y , fA$n *h+ -. .
KALSI ENGINEERING, INC.
ve :-.s :.. :. sc s s ~.. a s
l KALSI ENGINEERING, INC. ,
1 Document No.15600 May 25,1988 Appendix C )
Page 41 of 54 w
I I
KALBI ENGINEERING, INC.
DtSsGN & AN/ lysis CONSULTANTS cv Touta **0stC, esog wo d'. 2,
.u... C, OATt eoetbc~]S~n5001A~feA ,Wse~.J ses5~$ d Aegon5 A<h.a k Xaue~Xiisign;Acan%
nru. . _ _ .
dksi'~nsu6 h7s n W.
.._. __.Tht, eguableiam tulat.%shsps es Je -exprsuec/a a :
\
y . . . . .
l N cesIc' +,At, Nsin/t* = D.s _ _ _ .
-N .- ] Sy .s O. .. .
N- . -.
1 Os p p -..
,# A ....-_ _ _ . A N us /s'- Nsin / G* - w -At Ds = 0
- -u .
-W - - - - - - - . - - - - . - -
_ _ . . - p8 ..---
r -
._ .. _. . _ _ _ . .: N. .. .
l __ .- . . . . . . .
.(ebl/G*4s 31* ll'*b \ ment' ._
- - . ~ -sini
~
D, (p,C*80C" ust 4 Als31*l 0 mWt He s .-
~.. .. . .
. ll - Og >> W e ib t n -. .- .
l
. . . .. yg a he MLIS S I'* I I
O C*J /G* ~ Ato S / *!*
.7W&s We l20vs fls t b//en.,1)n g r%l4 tien t *
~ '. h, As, z,, ~
.. . _ _ #. 2 0 0.494 .
... -. . 0.1 S 0.SSS
. ... .0,30 0. 6 /8
_. - .... 0,SS 0. tit .
- . . Q. le o 0. ~14 ! .
. . . . . c. 4 F o . p/ f
.. ... . . . _. 0 . S'o 0.tt7 .
-- % cs/e e /sandAh is tAe nstninsum Co d cie,st of fet <Jan, twg.u,M ea.- - J. .- h, -m. .d_.h .e s t G w .,*/
M m we de J - s w i n t-4 _ KA LSI ENGIN EERING. INC. s c e-*sca. ce sos <. *s*. .. s
KALSI ENGINEERING, INC. Document No.1560C May 25,1988 Appendix C Page 42 of 54 l l KAL51 ENGINEERING, INC. DES 4GN & ANALYSIS CONSIATANT3 CUS'0Wie.peestc? ! pactwo (. 3 j DAvt Sv8stC' 0V i I
.weg, A t b $51n5_Nle s ~ &I & Nlci." f4 e s.ec.f .. \
. - CoM M .. Os . 74e c.de ve C.A/ s~lJul p, and /tu \
\
1 ddus4 AG XLr difase*ess de keen ,44o A d.,4h, att h19h se
. . . _ _ _ . . . l
_. f-k .zio., ecw m enly s< seel 4 f sea.'Y~a ,A t%.s/s nts . _ . .
. ~~] . <<s bt.5w in fo'e~h ~ee, c/;+tN, (sv&E *J t a 01Th Ah
_. c-u e~ ,
/y M d o(=$ a9 Wdedana [. Men.64,
$.'.'in an Uer/ elettyn Cools [a., SA EMSW ser5ses A.
... J & camh .z2k geA w,d .rejm e.,*
._. .. ._ l s A.<./J L.e i ..
.. _.__ A edif C.e.L tJ11'd ve ry //tfle foral.
e-pp /r ed w
. ..... th e w) *> s r e. .a-Iis . If r'Ae h a et. a g te se k a s date,rio estei...
/s.s/e+ #44 24. c4.s z 4, s A eM .24.s. M Ze.4 4 C.I ..
.N wp . fhss~ A L. Q e.y M n = .e ea.,. a.e m, '
. -- . t.u e4 mac.f M i Q cad M s tx4.s du (qs
&hk Al~* .0v ;.As at the segm s.sr rs.a[
. MM ).' .
7~ h a gs+< e at s y m s ,r k fc a m le
% s ,Q 4 /sef Ms/ V l OM 3eme deteeterafIm suit /, pa//,ory ms Jr.: . Th .s y L ,
$_Au cbfieis h$ frie,ttr,, cn fAe bnde&le so,if7 de hiyA '
A . e oc4~ Doc 5wy N$ rejm *~t ago M. D e s'* n4 e e 4'e fE** rs%
~
. _ _ . .mes.y de rf,e resdt pf repeJU fast c/es)ys o. d k puest .
l
. . _ . ekt .. .
. . . _D>e pre cassttmcq measure,mq he tocr+k pedrenting is h .**s.rure .d rt *c.a,.hvt ef t4e .thoes e ,J segon s.J rc.ils l
l l l KALSI ENGINEERING. INC. l va:-as *.:sss sr.asa.=ss l h
l KALSI ENGINEERING, INC. Document No.1560C May 25,1988 Appendix C Page 43 of 54
/
KAL51 EN GINEERING, INC. DESIGN 4 ANAkv515 CONSutJANTS custowen pac.get 9406 40 (=4 Daft Sul.E*? OV l
- . . dona n ot occw. ta hi e the volve pae c uing a,,a %mg -
... a.t my esd af 4e shvke . .
- 4. Load. en .Segme-r Rail
~;.;.f4e ~previen recJrm ducasses tAe Sdirirn fAcat- Se
^ v-R l.oc arm shoe ceulcl stick a.t A segment rail blows. i
~5nrAt~~se5A ,~wn .A5EtN' e~ Nac.* Me 'rd* *
- fuds O he ~.~
~
- ... . Cl tarn {ed .ee.W $41'/m AfG. t)e nsAsimesm /aa.nl en +/re run.il. . .- -.
. . __-_ . Assurn e f6e tsrersf cs.se & Fit
. . ons \
-)>e5444 f$ro ug h flr e lev 2 loc oMia . l j _
J " _ . . _ . _ - . . . . . . . . . . . ..
._E-em th e dCJs'g n lA.<f e uC~ s tv e b* vt-
. l . . . .
.. .. f.lc l'*.yuired CD CA/cHnt 80 bic.hrn 4 s :
-..# .- a 12"
..-. 24 M 6 - . .__.. . - . . . . ..
~. . . . . _ . . . . . .. . . . . . . .
. . . . .. . . g , ig o - 9o . so .= se ' .
5 . . . . . . - . . . ..
- u. 9 * ' A1: /.28 ..
~ o$ _....
% 74U ArpA cas%ciont of Atc han is
_ . - . . . . w _ .. _. .. . _ _ . .
.. . . n et p e ss .'s /g fc occ ur on o.en h.cr .
-... ~ MI .
su r4c< s +vn- with sem e galling .
~
'4 s*
' ,4',we,e r, /Ae a e A / e,r 4.e.t, Jos e..,'
33 ' .... W 1'b 6 P15*/ V e s.f, 0CCs4f s CLT Yb 9
.~ . .. .
. -. - /* w ev c- n u erf +4 e rut / c.Aa.ek
. . -.. . .. . . _- . a s tA w n i. rA e ,o Ic y ea! .1J.,tet. .
1 1 KALBI ENGIN E ERING, INC. vt O *a&N O A. O E S GN E. AN A. ' S 6 l l
i KALSI ENGINEERING, INC.
' Document No.1560C May 25,1988 Appendix C Page 44 of 54 '
i K ALSI ENGINEERING. INC. i Of SiON 4 ANALYSi$ CONSULiaNf3 CU$touta seo;tet 84Gt NO d'. (* 0478
$ Utst CT SV i
. . There&e ,+Ae indenMem of FAe clam Aw e.ne.--. .... . . . .er cou./d --
. inc rers e . . _ttie ceDcient af frishm /s tAe /evd in s .-
i
... - . . cJedLt< d c.10 e e .__. .. .. . . . .
. . . . . . . . . - I
_. . .. . . . .. . ... I
. .. ._ Z/ all rAe / cad eminy ostenents are shoy eno uf.k ., ... '
. .. . .. . . . . . . . - . - . . . . . . . . . . i
- Aen + tAe load *yp/, ed to botA. rails ca '
...reac4 4Go kips
^ ^ ^ ~
~bs~ edcJstd in .tec+a+ !.. . "*L . T.T.'_^.T ~ ~ 1
.-- . . . . . . . . . . . . . . . - - . . . . . . . . . . - . . ~ . . .
. . . S A mova /*tAll'5fic edf' ntI sta'r% . Ass u m t. fdC n &x im u m, '
l
~~ ~
. - . . /od n IAe hd 5 hon he sleT5[athe ~e<~,4.er.'.~ .
_ CueAc<s read,es &a mdered s Aese drms% . 7Aenfers,. .. . - .
~ ~ ~~~ '
C i A d i N To.iisxl'a.et59 iO
~ ~ ~ ' ' ~
SAtaf Wre y a/2Ts000 K C.6 = 7C, e oc Asi _
. . . . - _ . . [.r e .BHfr /rseo = ((,Jf.) /4. __. _ _ _ . .
J : #' . -
. ., ed, /2.s /h. - . . . . . . _ . . _ . _ . . . . .
. . . . _ . . ._ .. ces ss* . . ..
" ~
fy' a Ee cas li'= fo,4sm Ib G- . . . .
t fH ' & 3in / 7
- n 24, $4f /f , ,, , .
.ir! .
8.H an rya sdear.=. 50."to , a,aes & . . . .
. . . . . . . D w2 AoM mu . shea t- (Twarha e ot: twhayer.)
n ^5hlUL . su.m - _ BoM nw. hesi/e Yass ume So% S1 t),e ist bel &)
. C't ._..A
= _ . m: 60, M / M _. _ . _ _
L M 0.La L l l KALSI ENGINEERING, INC. l i vi:- s.c~ ce s ss e. s. .s s
. . . , . . . - . - - - . , . - -I
l KALSI ENGINEERING, INC. Document No.1560C l May 25,1988 Appendix C i Page 45 of 54 KALBI ENGINEERIN G, INC. etsion a aunvsis cousuttaars I CUStCWf a veost0? l sect he M. d 1
,v. t e, OAtt
~ '
'~ ~ ~ ~ ~^ l S/Na iA 5 ik of. N 55]o~/t. _ __'_..'. ' .____.-... . . - 1 1
_ _ . - CZ = 1 < , Q ' ..+ z ' a 117,. vCCjw.* > tur. %.* !?o k
. . . , gg. g j
. . .. 4 t
. ._ _.. _ ... . __ =/4e r4
. _ ..Therskr*, undu the eension ed high evsH, mal canditin.c, _
_ _ . _ . . _. . . m ..
~
?/>e maxima n> los4 de .seg n.a r_c 4 /s 4 ca.pe.L /* */ .rhesm
^'
~
ok.~t?t5/5.'~ Nalwi ]~5er'fs s5*id ]e per $m.~/o~ ~ ~ .~
^
de+5mine 5$<+Afo~tle~r 55e~s~$[9 t Aavc s/s?5h:45 A t c -- A tac doH A. /wec.s.. __. \
. . . _ . _ _ . . . . _ _ _ . . . .. \
. 7%< lev-bl.ac TAoes r#. rAe Ai/eet mst y gde Q s low
\
5evers 94Mkj ond .st race fsar-14 om /f e em+.d evus. flaflow9s ve also wstik e>,+/,e mi/ Sf'a, ,
..The new dem wirA sw % rws./..
s 4& n un i d carn ws _ --. s 4 e det de a4/e fe ksep . _.tfs c e& cts,,t.k heln.> th e D.c
~ ~
* ~
. tNUe ~ Jo avoid Q'L' asil M.
.. l O
V 1 1 KALSI ENGINEERING. INC. I v i: . s.ca. ss e .s asa. ,s s l _ . . _ _ _ . . . _ , ~ , - _ . _ _ _ _ _ . _ _ ,,
Document No.1560C, Revision 1 June 10,1988 Appendix D Page 46 of 54 O i l APPENDIX D ANALYSIS OF MSIV OPERABILITY DURING CLOSING WITH GUIDE RAILS BROKEN O i l l l
~
O KALSI ENGINEERING, INC. . ve:-.s :.. ci s ss s .s.. .. . l l
, - _ . _ , , . - . . - - - , - - - . - - - - - , - - - - - - - - - - - - - - ~ ~ - - - ~ ~ ~ - - ~ - ~ ~ ~ ~ ' ' ' ' ~ ~ ~ ~ - ~ ~ '
Document No.1560C, Revision 1 Appendix D June 10,1988 Page 47 of 54 APPENDIX D ANALYSIS OF MSIV OPERABILITY DURING CLOSING WITH GUIDE RAILS BROKEN INTRODUCTION This appendix addresses the analyses performed to determine the closing time of the W K M 40x30 MSIV gate valve under several different operating conditions. The conditions included determining the closing time of the valve with (1) no system pressure, (2) system pressure applied to the segment side , and (3) system pressure applied to the gate side (reverse flow direction expected under line break conditions) with both functioning and nonfunctioning guide rails. Condition 1 was analyzed to establish a basis of comparison for conditions 2 and 3. Under conditions 2 and 3, several load cases were analyzed to determine the effect of coefYicient of friction on closing time. The coefficient of friction was varied from 0.20 to 0.30 at the seat to-gate interface and from 0.25 to 0.30 at the gate and segment back angles. These cufficients of friction should bound the expected
' coefficients for the mating materials and operating conditions . The materials of construction for the mating surfaces are Stellite overlay versus Stellite overlay for the seat- i to gate interface and 17-4PH stainless steel versus 17 4PH stainless steel for the gate and segment back angles. t The system operating conditions under normal flow conditions are:
Normal Operating Pressure: 1,085 psia Normal Operating Temperature: 554' F l Steam Flow Rate at 100 percent: 2,093 lbesec l Steam Flow Rate at 105 percent: 2,198 lbs/see l The system operating conditions under line break conditions are: Operating Pressure: 789 psia Steam Flow Rates: 6,000 lbvsee at time = 0 sees 5,000 lbs/see at time = 1.5 to 2.0 sees linearly fror,n.5,000 to 0 lbvsee between 2.0 and 3.0 sees O KALSI E NGIN E ERING, INC. vt = AN Oa. Of S GN & AN A. v5 S
1 Document No.1560C, Revision 1 Appendix D June 10,1988 Page 48 of 54 r For this analysis the design operating conditions and Gow at 105 percent are used in the normal Gow direction, and the line break conditions are used in the reverse Dow direction. All closing times were calculated using a nitrogen charging pressure of 2410 psi whleh will produce W.K M's recommended nitrogen charge pressure of 2,500 psi at 100*F. This nitrogen charging pressure,2,410 psi, corresponds to the required charging pressure at 80'F (reference Kalsi Engineering Report No.1522 to W.K M dated June 19,1987). Gate and Segment Description The W K M MSIV gate valve (Figure 1) is of a double wedge, through conduit design that expands and wedges the segment piece and gate piece against their respective seats at each end of the gate stroke. During travel to either opened or closed position, the segment and gate are held in place relative to each other by lever locks that ride against guide rails attached to the segment and gate skirts. When functioning properly the gate assembly can be used bi directionally with essentially the same thrust and time required to actuate from the fully opened to the fully closed position. When malfunctioning (that is, the segment and O gate are not held in place), premature expansion of the gate occurs, resulting in increased Q ' frictional resistance at the seat interfaces. Because this valve has to perform a safety related function just in the closing direction, only the effect of malfunctioning guide rails in the close direction will be evaluated. As shown in Figure D.1, the effect of malfunctioning guide rails af.eets the closing time of the valve only when the pressure is applied to the gate side and the segment drags on its mating seat. Under the normal Dow direction the impetus for the gate and segment to prematurely wedge can develop only if the segment is impeded from moving down with the gate and the guide rails are not functioning. The required impetus for wedging will not exist during downward travel because the segment, due to its weight, will rest on the lower angle of the gate as shown in Figure D.1(a). The lower angle of the gate is opposite the gate movement and can not cause wedging of the assembly. Under reverse now, premature wedging in the mid travel position will happen only when the guide rails are not functioning and the lever locks are not preventing relative motion between the gate and segment. Under reverse Cow conditions, the force applied to the stem to O KALSI ENGIN EERING, INC. c:-.s:..:asosr..s.oas
Document No.1560C, Revision 1 June 10,1988 Appendix D Page 49 of 54 O overcome the segment drag due to differential pressure and friction is transmitted through the top angle of the gate as shown in Figure D.1(b), thus causing wedging. V 1r m 4 , s sN ,. s R.OW , R.OW l I l __ l ~
,6 l
'J FIGURE D.1(a) FIGURE D.1(b)
NORMAL FLOW DIRECTION REVERSE FLOW DIRECTION I For all load cases involving pressure, the difTerential pressure acting against the gate assembly was varied linearly as a function of the gate stroke. At the fully opened position the differential pressure was set to zero psi, and at the fully closed position the differential pressure was set to 1,085 psi for the normal flow direction and 789 psi for the reverse flow direction. Comparison of the loads produced by this pressure distribution against that produced by conventional drag equations shows that the approach used in our analyses gives higher normal loads, thus a more conservative solution. KALRl ENGINEERING, INC. vt;=aN Oa. OE S GN r. ANa.vS S
L Document No.1560C, Revision 1 June 10,1988 Appendix D Page 50 of 54 O Additional load cases that do not consider premature wedging were analyzed to compare the valve closing times. Closing times were compared for both functional and fsJled guide rails conditions; the results are tabulated in Table 1 of this appendix. The effects of variance of the coefficient of friction on the closing time are presented in Table 2. O l 1 i i O KAL51 ENGIN EE RING, INC. vs :-*s :*. es sos e. .s.. .. .
Document No.1560C, Revision 1 June 10,1988 ! Appendix D Page 51 of 54 CONCLUSIONS The following conclusions are broken down into the expected valve operating conditions. The results of the coefficients of friction combinations presented here are those most likely to exist. An expanded matrix of results using different coefYicients of friction is given in Table 2. Test Conditiom l No pressure and the guide rails operating properly. This condition is included to determine what closing time difference to expect during normal system operation after the valve has ! been tested with no system flow. This condition should never exist under normal plant { operations. I The calculated time to close the valve (31.25 inches of stroke) was 2.50 seconds. l Normal Conditiom
^
l Pressure of1,085 psi acting from the segment side and the guide rails are functional. This ' condition is the normal operation of the plant. i The calculated time to close the valve (31.25 inches of stroke) was 2.82 seconds with a coefficient of friction of 0.25 at the gate to seat interface. l Abnormal Condition: Pressure of 789 psi acting from the gate side and the guide rails not functional. This 1 i condition is the most severe possible with regard to the valve closing speed. 1 The calculated time to close the valve (31.25 inches of stroke) was 3.20 seconds with a ; coefficient of friction of 0.25 at the gate-to seat interface and a coefficient of friction of 0.30 at the gate and segment back angles. Using a coefficient of friction of 0.25 between the seats and gate assembly and a conservative coefficient .sf friction of 0.25 at the gate and segment back angles, the valve will close in 3.41 seconds. O KALSI E NGIN E ERING, INC.
.e:-.s:..: .csc..s.o ..
1 l Document No.1560C, Revision 1 June 10,1988 Appendix D Page 52 cf 54 O ANALYSIS PROCEDURE The analysis procedure used to solve for the closing time is the same as that used in the previous calculations performed and documented under Kalsi Engineering Report 1522 to W K M dated June 19,1987. The program was modified to include resistance of the piston seals in the actuator and to include the efTects of both internal body pressure and differential pressure acting across the gate. For the load cases where frictional resistance exists at the segment and the guide rails are not functioning, the required force to actuate the gate is given by F= Thrust Force v l GATE 42 N SEGMENT l N TP= Additional Resistance DS ' ' 1 Ds TL 42N iL M1 D s 41 D s ; l M a yA X EFy=0 F = [sina (14142) + ces a (41 + 42)) N E Fx = 0 D. = (cosG- 42 sina)N EFy= 0 P = (sina + M2 cosa)N - t Ds Also P = ,6 Pressure x Gate Exposed Area x pt O V KALSI E NGIN EE RING, IN C. v.:-as: .ca. ass,as.o.. ' I
Document No.1560C, Revision 1 June 10,1988 Appendix D Page 53 cf 54 O Solving using a friction coemeient of 0.25 at the seats and a friction coemeient of 0.30 at the gate and segment back angles yields the results shown in Table 1. It is expected that the coemeient of friction at the seats will be a maximum of 0.25 because it is a dynamic interface, and that the coemeient of friction at the back angles will be at least 0.30 because the mating materials (17 4PH vs 17 4PH) are not considered good sliding materials and are acting in a static mode. For the normal flow direction a differential pressure of 1,085 psi was applied across the gate, and for the reverse flow direction a differential pressure of 789 psi was applied. TABLE 1 Time to Clone in Seconda No Flow Normal Flow Reverse Flow Direction Direction l l Rails 2.50 2.82 2.71 i Funetional j Gate Rai! 2.50 2.82 2.71 Nonfunctional Segment Rail 2.50 2.82 3.20 l Nonfunctional i I Gate and Segment 2.50 2.82 3.20 l Rails Nonfunctional These results show that even under reverse flow the gate will stroke the complete distance under realistic coemeients of friction. The gate inertia has not been taken into account in these analyses. The effect of changing the coemeient of friction at the seats and back angles produces the following results. 1 O t KALSI E NGIN EERING, INC. vi:-. sci.:esosr..s...se i l l
Document No.1560C, Revision 1 June 10,1988 Appendix D Page 51 of 54 TABLE 2 Closing Pressure g g Time Canmets 0 0.25 0.30 2.50 sees Rails Functional, Normal Flow 1085 0.20 0.30 2.75 sees Rails Functional, Normal Flow 1065 0.25 0.30 2.82 sees Rails Functional, Normal Flow 1065 0.30 0.30 2.90 sees Rails Functional, Normal Flow 789 0.25 0.25 2.71 sees Segment Rails Functional, Reverse Flow 789 0.20 0.25 2.90 sees Segment Rails Failed, Reverse Flow 789 0.20 0.30 2.86 sees Segment Rails Failed, Reverse Flow 789 0.25 0.25 3.41 sees Segment Rails Failed, Reverse Flow 789 0.25 0.30 3.20 sees Segment Rails Failed, Reverse Flow 789 0.30 0.30 - Segment Rails Failed, Reverse Flow, ' Gate traveled only 28.4"in 3.37 sees These results show that only one condition will prevent the gate from closing completely; but it is highly unlikely that the coefneient of friction will be as high as 0.30 at the seats because it is a dynamic sliding surface. It is also highly unlikely that the segment rail will fail with the new design since during normal operation it sees very little load and is called upon to act only when the gate is unwedged from the closed position, during which time the travel velocity is extremely slow. The detailed computer printouts are not included in this appendix, but are available upon request. O V KALSI ENGINEERING, INC. vu -.s :*, :e s v, c. .s.. .s
O E.R. 7834 E.O. 25504-01 FAmM MarM OF '!HE 40" X 30" CIASS 900 mFAR GAIT VAINE u IIITISIANA IOIER AE LIG@ N 13 k?00 I O l
l l TAB 2 OF CDm!NIS O 1. IFRIX)CPICN 1
- 2. VAINE IMNTIFICEPICE I l
- 3. INVESTIGATIVE RESUI2S 3.1 VAINE S/N 506158 3.2 VAINE S/N 506157 I l
- 4. CDHCIUSICNS
- 5. RECD 9ENDATICH
- 6. DISCESICH OF ANAI2 SIS APPENDIX A: CIDSING TIME RECIRD MO( IIXTISIANA PCHER AND IJGfr j l
APPENDIX B: BOIT SHEAR SIRESS 'IE!Tr DATA AND RESULT APPENDIX C: I.EV-R-IDC SIEES AND GAIE SIIE SEAT SKIRT GJIIE RAIL IMPACT ANAI2 SIS IIRDC WPmTE CIIEE SIKEE 1 APPENDIX D: EAISI DGINEZRING VAINE CIOSING TIME CAIIITIATICH RERRF APPENDIX E: BOIT SIRESS ANAI2 SIS - MISALICH4ENT CCNSIMRATICNS l APPENDIX F: METAIURGICAL ANAI2 SIS REERP APPENDIX G: VAINE CDGOOff PICIURES 1 1 l l l O l 1 i
'EA l
r b
i FLOW CONTROL O w E. R. 7834 1 10: E. O. 25504-001 i MM: Tri C. Is, Erugineering Aralysis SUBTECT: Failuru Analysis of the 40" X 30" CIASS 900 )naclear Gata Valve for Imisiana Power & Lit:t DA1Y: May 6, 1988 REVISED: June 13, 1988 per IML's May 31, 1988 Ctamments INIRXUCTI21: During a recent a2tage of the rentiniana Power and Light (IML) Waterford (3 ruclear power plant, inspectim of a main turbine throttle valve revealed a piece of the 40"x30" Class 900 Main Steam Isolatim Valve (EIV) gata skirt rail and several heads frcus failed flat head cap scruus. There are two 40"x30" MSIV's utilized in the IML system. 1he separata particm of the skirt rail was marked with "W-K-M 261661", W11 cit airiari in identificaticm. Prior to this cutage and main turbine throttle valve trap 14= par +1m1, the EIV was totally functicmal with to indicatim of pechlemus. The valve had seen agtminately six years of service. Upm finiing the failed parts in the turbine staaet trap, IML decided to investigate the two EIV's, resulting in disassembly of the two valves. This report is h ==1 ting Flow Ototrol's failure analysis, ocmclusions and ram =andaticns haanri tpcm parts ard data sugplied by IML. VALVE IGNTIFICATICE: E124A (Ch-Sita) E 124B (N4maa_M City Plant) B/M 247093 B/M 247093 S/N 506157 S/N 506158 P O Bon 2117 Houston, Texas 77252 2117 (713)499 8511 Teten 166282 l OEVCC*
- LAAKINe e THORNMILL CRAVEA*
W.K V*
- WHEEUNG VACHINE* PRODUCTS
i E.R. 7834 E.O. 25504-001 5/06/88 Page 3 Revised 6/13/88 O --- Valve S/N: 506158
'Diis valve was dihlad cm site with Flow Ot 1 trol engineer, Gary Racal, and servicaean, David Ray, present. '!he stas, geta/ segment ammably, sepent skirt assembly, the gata skirt bec$t and failed rails were fonem$ed to Flow Omtrol l Mi-M city's facility for evaluatim. 'the following aboarvatims were made:
- 1. Ikyth of the Inv-R-Icc gata skirt guide rails had sogarstad fra the seat skirt. All of the retaining bolts attaciting the guide rails to the east skirt had separated cm the unting plane of the guide rail and the seat skirt.
- 2. 'Ihm rail lockyed in the main turbine throttle valve strainer was in two pieces. 'Ihe rail was broken out of the rail to skirt mounting bolt holes.
- 3. Both of the secpnent seat skirt gaide rails were in place; however, sczna of the bolt heads had broken at the bottcan of the ocmical bolt head at the root diamatar of the first thread.
- 4. Light to heavy galling marks were found cs) the botta of the Isv-R-In::
shoes where the shoe ocmtacted the <piida rails &tring the closing stroke. Heavy galling marks were also found cm the tg side of the Inv-R-Icc shoes 1 dure the shoe ocritacted the guide rails & Iring the opening stroke.
- 5. Li#tt to heavy galling marks were found between the gata and secpeant back angle. Li@st gallinrJ aarks were also found m the gate and the seat skirts.
- 6. Records furnished by IML gave the final "as-left" closure times frt:en surveillance testirrJ ocmchacted by IML to satisfy 'I4cimical Spe::ificaticm requiriments. A copy of these records is included in APPENDIX A. 'Ihase records indicate the valve has experienced a 0.9 seccni closing and an average closing time of 2.189 secc:1ds.
- 7. F2xun the bolt shear stress test data in APPENDIX B, the following data was obtained: l
- a. 'Iha new bolt from Flow Q:ritrol inventory had a shear stress avr=aa of 107,981 PSI.
- b. A bolt taken from the sbject valve earpnarit skirt had a shear strees value of 81,729 PSI. 'the failed surface of the bolts indicated a surface flaw at the thread root appruimately 0.1 incts deep.
'Ihe pictures of all of these facts are included in APPENDIX G.
O
i E.R. 7834 E.O. 25504-001 5/06/88 Pege 3 Revised 6/13/88 l Q Valve S/N 506157
'Ihis valve was di=ama=hled on site with Flow Q:ritrol servioman, David Ray, present. '!he parts were not serit to Flow Q:ntrol Misscuri City for evaluation as part of the analysis. However, the W admi taken by David Ray and diam ==icos with IML sita perscrinal were used. 'Ihm following cheervatims were made:
- 1. On the secpnent side seat skirt:
- a. Ik:th of the guide rails are in place.
- b. Frue the back side of the seat skirt, the two lowest bolt heads of the ri$1t hand guide rail wars separated, and the lowest bolt head of the left hand guide rail was also separated.
- c. 'Ibere are slight galling marks cn the lower guide rail angles. 'there is a slight separaticn of the lower ends of the guide rails frun the seat skirt.
- 2. On the gate side seat skirt:
- a. Both of the guide rails are in place.
- b. Fran the back side of the seat skirt, starting frue the lower and, the No. 3 bolt head of the ri$:t hand guide rail was separated, and the three lowest bolt heads of the left hand guide rail were also separated,
- c. 'Ihart are light to heavy gallirq sarks on the guide rail angles.
- 3. On the Isv-R-Icc arm shoes:
- a. 'Ihere are heavy galling marks cn the top of the shoes similar, but not as heavy as valve S/N 506158.
- b. 'Ibere are heavy gallirq narks cm the bottcut of the shoes similar, b2t not as heavy as valve S/N 506158.
All of this data is shown in the pictures in APIMDIX G.
'Iha locaticris and charactaristim of the galling marks of all of the w-As of this valve are identical to that of the E124B valve. 'Ihus, we can concitda that this valve experienced the same cperating ocrxiiticn as the E124B valve.
CCNCIDSIGtS: 1.
'Ihe EIV with gas spring actuator vill pede its intended safety functicn, closirg at a failure signal, even withcut the gata skirt rails in place. In the twmnal flow directicm, closing of the valve is not d=ga Ad.
cn the guide rails. 'Iberefuru, functioning and closing times are i@At. of the guide rails. 2. Separated rails do not hamper the closing stroke (safety positicn) of the valve. Rails which separata ch2e to gravity will fall into the lower O barnigherical sectico of the valve body. On this heisgherical surface, any load cn the rail vill nost likely beid or push the rail aside. 'Ihis affect was seen in both of the failed and separated rails.
l E.R. 7834 E.O. 15504-001 5/06/88 l Page 4 l Revised 6/13/88 ! l
- 3. During the closing stroke with the gas agring actuator, loadirg of the skirt rails is a dynamic iW and is *=4*ad Wien:
i
- a. The valve closing time is less than three (3) seccmds, (See i APR M EX C)
- b. ;
The coefficient is naviairad of fricticrt (galling surfaans), betweenandthe Imv-R-Icc shoe ard skirt rail
- c. A single rail / shoe aberw+= the ocaiplete load. (See APRNDIX C)
I
- 4. Scais of the retaining flat head osp scrus examiined acritained material flaws, W11ch severely limits the amount of energy which could be *- ;-J during the closing stroke. The shear stress .L-yun of the flawed bolt is 76 W-L of the non-flawed ):olt (See APRNEX B) . D2 ring the dynsaic inpact acds of closing, it is W ad that the notch sensitivity a-~iated with the flawed bolt r=^r== the load carrying r= Pity acre t severely than the rechrtics) in ahear strees indicates (See APPENDIX F for a ocupleta metallurtyical analysis report).
5. Bolt hole /alicpment is a secxrdary elemurit in the flat head cap screw head separaticr) (See APH!NDIX E) .
- 6. 1he failure of the bolts attaching the guide rail and the gate seat skirt together is the result of a ocabination of factors: a) flawed bolts, b) '
cperaticri time, and c) impact load. The calculated bolt ahear stress results frtaa this navim m iW load (closing time of 1.588 seacrds ard the impact Iced is linearly distributed) is 235,846 PSI verwus a failed Ot ahear strees of 81,729 IBI (See APPENEX C). j 1
- 7. Inp%t load transmitted to the rails ard retaining bolts is sensitive to: {
- a. The closing time, !
b. The coefficient of friction between the shoe ard rall. Decranaam in closing time or increases in coefficient of friction between the shoe ard rail incrma=== the retaining bolt stress ard possibility of failure (See APPENDIX C) . 8. Several desigr) enhanoaments can be nede to regiaos the transfer of energy /lood to the rails and also imprtwo the integrity of the mechanism. The enharrumarits are as follows:
- a. T 4mid penetrant examinaticri of the retaining bolts.
- b. Modify the profiles of the skirt rails ard shoes to decrease the transfer of the closing force into the rail ard bolting ( see APPENDIX C).
- c. Provido a ncn-galling natarial etabinaticri in the load i bearirg/ transfer area of the shoes ard rails. Use of Stallite 6 ard nitridad StalI4.ta 6 (See APPENDIX C) .
9. The gallirg marl m 'he tcp of the Inv-R-Icc shoe ard the guide rails of l the me<Jmarit side h ' akirt are the result of high friction coefficient ard high cxr1 tact stress betwem) the two + -.ds. A design erhar ---d. simi.lar to that detailed in Ocricluelcr1 #8 is aplicable in this area.
E.R. 7834 E.O. 25504-001 5/ 06/88 ! Fege 5 Revised 6/13/88 RB:XNIENDATIGE:
- 1. All not retainirg boltirg utilized for the skirts, should have a surface
, NIE to eliminate possibility of surface flaw in the retaining boltirg.
- 2. Overlay the Imy-R-Icc shoe (all amm1d its ciramiferince) an1 the top of the guide rails to lower the coefficient of fricticn and eliminata the galling probability between the slidirg w-.Am.
- 3. Omnging the start and and angles of the guide rails of the seat skirts to reduce the ocntact force and also re& ace the ocritact stress and rdv,n the galling pre lans between the sliding + As.
- 4. Hitzdardenirg the Inv-R-Ioc shoes will further enhance the sliding ocnditicn of the sines.
- 5. Otritrol the amount of minaligrunent of the bolt holes in the guide rails and the seat skirts will prevent the bolt heads frun separating die to side loads.
- 6. Increase cicairg stroka time if possible with w=kuints of the systen reglirements.
DISQJSSICN OF ANALYSIS: Upon dinaammehly of valve 16124B, it was foiz1d that the guide rails on the gate side (down stream) were separated from the seat skirt. 'the bolts to attach the guide rails to the seat skirt wears aheared at the interface plane between the guide rail and the seat skirt. One (1) of the guida rails was broken into tho (2) pieces. 'Ihare were light to heavy galling marka, cm the guida rails W1ere the shoes ocne in ocritact with the guide rails from the wedge open position.
'Ibe guide rails cn the secynant sida (upstress) seat skirt aru intact, however, scue of the bolts warm separated at the botta of the ocnical band (at the first thread root diameter). 'Ihm failed bolts are located mostly truard the bottcan of the seat skirt. 'Ibers are light to heavy rpillhg marios at the guide rail argle where the shoes ocritacted the guide rails from the wedge closed positicn.
'Ihe IAV-R-Inc arms of the valve are in good condition, however, heavy gallirg marks were found cm the tcp ard bottcan of the shcus where the shoe octfm the guide rails fran both wedge closed and wedge cpen positicris.
'Ihe back argle of the gate and se;pnent are galled frca the heavy wedging force.
'Ihe pictures to show the above ocniitions are inctitded in APPENDIX G.
i O
i E.R. 7834 E.O. 25504-001 5/06/88 Page 6 Revised 6/13/84 Follu;ing is the riina==icm of the failure analysis: From the tolerance study, ths geta/segnant hif travels a nav4= = asrxmt of 3.8" before the Imy-R-Inc shoe oczitacts and impacts the skirt rail. The degree of impact is depended upcm the following perumstars: 1 a. Metal coefficient of friction of the guide rail and the MInc j eboe.
- b. 1he relative position of the @ rail angle ard the Imy-R Ioc shoe
' contact point.
- c. The travel velocity of the actuator pisten upon impact.1his velocity is a fLmetice of the required closing time.
At the ocntact point, there is a ocntact normal force and n frictimal force ' a (the fricticmel force ecpalm to the normal force times tas ocefficient of fricticm) . 1his frictional force is actirvy in the opposita directicm of the sliding noticm of the shoe cm the guide rail angle. FIauR21 - Wsw ORN POSITICH d M M y O ' '
.p.L4m+a y sMALL
, f l NosswT luxiwtr 80 x e g t s e oic a.
/ 1 O
( ! ye v' F#q A
,a a
\
8 l G ul D E R A I L. G0 ICE RAit I .O
. _m _ - - . . .
i E.R. 7834 E.O. 25504-001 5/06/88 Pugs 7 Revised 6/13/88 O 11 ' 2 - > r== cu: = >o -<= U
/
N I
\.N M
d Og Guion uit, ums, the higher the coefficient of friction the larger the force. In the event the frictium1 force is too high, the twsultant force (of the fricticnal focus and the normal force) directice would cause a small or reverse umant to prevent the gata and sepent frta unwe& J ing (See Figure la). Du full ispect energy is almorbed by the guide rail and the guide rail bolting. She result of the calculaticn in APPENDIX C shows that the force frta the impact of the E124B valve with closing time of 1.588 sec. is high enou$1 to shear the bolt (I W ahear stress is 235,845 PSI) . ;
., onging - gum. rau .ng1., overisying m .m. raus - -
shoes to reinos the coefficient of friction, and changing the directicm of the resultant fo ce (rmaal force and the fricticmal fcree), caly a partial of the impact energy is to be h by the guide rails and guide rail's bolts (see Figure Ib).1he result of the calculatica in APPENDIX C shows that the ahear stress in the bolt is auch man 11er than the bolt allowable stress (3052 PSI VS. 8330 PSI). lean the valve is starting to open from the wedge ciceed position by means of the hydraulic pressure in the actuator, and if the vertical w-m of the fricticnal forces between the bedt angle of the gate and segment is hi@er than the sepent weicAt and the sepent drag, the gate /sepent hly moves in the expanded positicm until the Inv-R-Ioc shoe contacts the guide rail, and tries to urwedge the gate and sepent. Again, at the ccntact point, if the ocefficient of fricticn is too hicA, the resultant of the normal ocritact force and its fricticmal wi d. would cause the guide rail bolts to tinny., significantly high tensile and shear leads, and cmune failure in the bolts. These forces would further increase ch.as to the hi@ fricticmal force between the back angle of the gata and sepent. In order to eliminata the above prcblem, the sans modificatico can be applied to rwh's the coefficient of fricticn. O l l ___ _ _ _ _ . _._ . __,___._. _. _ _ _ _ __. a
E.R. 7834 E.O. 25504-001 5/06/04 page 8 Revised 6/13/88 operational modificatice to ircrease the valve closing time would also rahaar the moviry parts velocity and decreene the degree of iW. celaalsticm in APPIINDIX C shoWe that by decreening the closing time to mate then 3 sectmde, the resultirg level streme, thich is almost even neglible.in the worst case (bridt wall), analysis is zwswwi to a Bolt ahear streme tests were performeri cm a new bolt and also cm an socisting bolt from the subject valve. The test a.W, and tant remit are included in the APRMEX B. 'Ihe existing bolt une fewd to have a surface flaw at the root of the thrend right at the interface plane of the two untirg % i.s. 'Ihis bolt is located in the segment side s~it skirt, there most of the bolts failed at the first thrend ridit underneath of the bolt head. Prepared by: - Trit.4ah Le, Project Engineer AEproved by: .
- A J.R. BrinkTey, Chief Engineer M
Kalsi report, the calculatisme, Engineering cm May 6,1988. etc., have been reviewed with Dr. J.K. Mang of f I l [ i l I
u.o-ee a m.' = ema.a mm -_ ,.aa w.o-.ae a. _ m..m n,4sw aes_.-,%w, s - - w -m__-a, m_. r ---- --_ _ _ . -w-_--- - - - - - - _ .-- J E.1 7834 E.O. 25504-001 APPBEIZX A
** "" **"" "==== ~ ~ u=
O l 1 i f 1
) -re,--, ,,, ,---,, ------n-v__ __ .,_, _.
Page 1 O us to v> 4
. . ... . ll15lE5 .a.ts sec
.'l/1/ F5 4. F4
. 9/I3/76 . .d. 53
. . 9/W/*s .
J, 53 I3 h1 lgs . a.51. S / 3-/ t G .. .. . 9 SL
. .. 3l2S 76 .. . . . . ?' S M!!/ *4 .. .. # 4 . . . . . . .
.. lt!l7b. .. .. 3.Il
... NS/298-
. ///5/F5 0 , 9 u c.
. 5//6/ vs /. 9 3 ,
... E//9/ F5 1,77 2
,_. . . _ . . . . . . 9/'4/85__.. l. 96 .' ... .__
, . / 2.// 2./ 8s /.92.
,. . . 3/2.1/76 /.7 7
. .. . 3 / L 2 / 7 6 .... .2, / S .
. . 3 /12-/T.S... . .- / 9 7 .. '. ._ . . .
; ,/ii/*6. s.+
7/'t /76 .._ 3. 2.
... ' // 3 /8 7 Q FY 8/t 3 /8 7 d. 4 7
-- _,-----,,---w - - - - - ----- --- - , _ -- -- -- - - - (P4 L g3 Page 2 M.s ID H & W
=l sc -
1 I
. 1 I
v w I l 4 :
)
t o 1 (J
, i ,
J l 1 j -
/
1 - g ,. , H 4 O - 3 i l l
,, ..n ,
~ . .
- - -. --,, - -- , ._,,_ ,. - .,-.- I
Page 2 Hs ID4 A 6 ,, o e 8 , d , i H
. K l @
8 e Ir O i ~ n 3 g ,, Y
. .E !
b a F 1 kt=
)
H 3 1 a il V 6 V O
.. ,3,.
l
..___.-_-_.__------..._...--l
0
^
t LP+ L 63 hs WH & Gme Sipa S ues (Dow us,ese) O t .u- a, s- v - % To p O O O M BADY o 0 0 0 0 0 0 54,0WE3 -40
- c: Beemu j
Pee rfanuac Parn no, s= <nur Sin Gma > ae. os 6ma Scirev ,
-- - -- , .. - -..- ,--,---- ,,-.-n.-. , , , - , . . - -
. . . . . ., l LP4 L /d,3 Ms ; ;g y p g,,, 3 BGNSNT 81DE $kitT (UP818884M)
O t o.< a as 5 - =
- d --
TOP 1 I O i 0 0 l 0 0 0 , l O , a 0 0 0 0 0 m Bum Ba.rs R v a Sws l s.-~/o H $wtogs i W .itsg y ' G 1,,s : O Paa x.auau cant vot. c. e . s i o n o u io ..s ; A E E. 00 S E (* H E N T S M ' R ~I
_g, _a - - - - . - - - - - - - - - - - - - - . - --- 9 l i I i D t E.R. 7834 E.O. 25504-001 APPENDJ?! B -- BOLT SHEAR SIRESS E!FP DMA AND ICSULT l l
Page 1 APPB E X B E. R. 7834 BgLT SHEhR mRESS TEsr O mis test ses performed to de mmine e the loa 4'deformatica curve of a new unloaded 5/8" 11NC Socket Flat Head Cap screw taken frta Flow Ocattrol Inventory and also of a screw removed fram the segnant skirt assembly of cme of the LP&L 40"x30" MIV's. i 2a new bolt 170,000 PSI and taken frtal .L a Yield inventory is with the ultimate tensile .L-yth of I gth of 150,000 MI. his new bolt is to have material ocupatible with the bolt used in the subject valve. A test fixture, Illustration 1 and %.elas, was annufactured to hold a partion of the failed skirt assembly. A plata simulating the skirt bacg was made and bolted to portion of the failed skirt assembly and loaded as shown by a Tenius olmen tensile testing machine. TW tests were ccrducted: one with the new bolt frtan inventory and cna with a bolt from the segnant skirt from valve l S/N 506158. Dynmaic impact testing was not sinnlated. Both bolts tasted failed in pure shear, however, the old bolt showed ann 11er deformation than the new bolt for the same bolt shaar load. Review of the , failed plane, shear secticoresultirq revealed an lower in the inclusicn at to loads the root dimn. tar of the thread cm the shaar. i i CAIIUIATICH OF THE IDLT SHEAR IERH9&ICH: Frtaa the test set @, the dial indicator il measures the total shear deformaticn of the bolt and the bendig plus ocapressive defcematicms of the test fixture.
%e testdial indicator #2 ==amnw the bendisq and ocapressive deformations of the fixture:
- %e bending readings. deformation will be subtractive to the dial indicator il 2e cxmpressive deformaticn be indicator #1 rendirq.
will subtractive to the dial Thus: Displar,=narzt = Dial Ind. #1 runding - Dial Ind. #2 reading Ibit spring stiffness calculaticm: K (IE/IN) = IIAD / DISPUGMENT. To calculata excgt the average the highest ard the sprirq lowest.stiffness, all of the data points are being used The attached table and chart are the result of the tast. O
t Page 2 FORCE PORTION OF FAILED RETAINING FLAT HEAD SKIRT RAll SOCKET CAP SCREW
<P /
4
<> lh, i
y T SEA SK RT B 8:F ll l{ l l{ i 1 "C" 'l il i PLATE WIDTH THICKNESS
\/ 'i '
' ,I "A"
"B" 3.75 3.75 1.00 1.00
'i "C" 2.59 I.50
{ O O \ DIAL INO. - LOAD F1XTURE i
'I
( 1 "A" "B" OIAL INO. j/
/
O s.0 TYP ILLUSTRATION 1 BOLT SHEAR STRESS TEST FlXTURE E.O. 25504-001 E.R. 7834
BOLT TEST RESULTt TEST Gas NEW BOLT. O . D '. o 0.507 IN. Page 3 LOAD IND. fl IND. 82 DISP. DIA. RED.SPR. STF. (LBS) (IN) (IN) (IN) % (LBS/IN) ps 0 0.000 0.000 0.000 0 125865.3 sJ 1000 0.014 0.006 0.008 2 146842.8 2000 0.024 0.010 0.014 3 174825.1 3000 0.031 0.014 0.017 3 205444.2 4000 0.039 0.019 0.019 5000 4 199920.0 0.048 0.022 0.025 5 208188.7 6000 0.057 0.028 0.029 7000 6 218784.1 0.064 0.032 0.032 6 229852.0 8000 0.072 0.037 0.035 7 236966.8 9000 0.080 0.042 0.038 7 242983.8 10000 0.087 0.046 0.041 8 248138.9 11000 0.095 0.050 0.044 9 248087.6 12000 0.102 0.054 0.048 10 252206.8 13000 '0.110 0.058 0.052 10 249621.1 14000 0.118 0.061 0.056 11 245398.7 15000 0.126 0.065 0.061 12 243661.0 16000 0.134 0.068 0.066 13 240435.6 17000 0.143 0.072 0.071 14 234956.2 18000 0.151 0.074 0.077 15 231664.9 { 19000 0.159 0.077 0.082 16 231427.9 20000 0.166 0.080 0.086 17 233437.0 21000 0.173 0.083 0.090 21800 18 171707.6 0.210 0.083 0.127 25 N/A l SPRING STIFFNESS = 230315.8 l t FAILEO SHEAR STRESS (PSI) =107981.8 TEST 82: OLD BOLT O.D. = 0.507 IN. LOAD IND. Il IND. 82 DISP. DIA. RED.SPR. STF. (LBS) (IN) (IN) (IN) % (LBS/IN) 0 0.000 0.000 0.0000 0 95238.09 1000 0.020 0.009 0.0105 2000 2 125000 0.030 0.014 0.0160 3 136363.6 l 3000 0.042 0.020 0.0220 4000 4 140350.8 0.054 0.025 0.0285 6 147058.8 5000 0.064 0.030 0.0340 6000 0.072 7 162162.1 0.035 0.0370 7 175000 7000 0.080 0.040 0.0400 8000 0.089 8 183908.0 0.045 0.0435 9 191489.3 9000 0.096 0.049 0.0470 10000 9 .200000 0.104 0.054 0.0500 10 207547.1 11000 0.111 0.058 0.0530 12000 0.120 10 205128.2 0.062 0.0585 12 203125 13000 0.130 0.066 0.0640 14000 13 198581.5 0.139 0.069 0.0705 14 200000 15000 0.147 0.072 0.0750 16000 0.157 15 198757.7 0.076 0.0805 16 178378.3 16500 0.170 0.078 0.0925 18 0 SPRING STIFFNESS = O 178303.1 FAILED SHEAR STRESS (PSI) =81729.36
O 0 n
~
in
-1 -
(n - -
>J b
zb -
- 8 I g O
Hot . _JR og co _
-h{+ O B a 1 .- -
g M$ _J 5 .
'h b E
<b b zE _ 8 <o 5 in z D . g . o J i i i i i i i a o i i i Q"~"8 o o o 6 8 6 B 6 8 6 8a9 6 6 i 8 i 5 g 6 6 6 y aard (NI) NO!1YWWD.GO
l l l 1 ' t
)
l 1 l O 1 i l l E.R. 7834 E.O. 25504-001 APPENDIX C W-R-IDC SHMS AND GATE SIIE SEAT SIGRT GrJIIE RAIL O N ANAISYIS IIRING MEDGDG CICSE S'IKEE i O 1 1
j . l APPB G X C Page 1 E. R. 7834
\
IMPIC.T ANALYSIS. l l I ANALYSIS EXPIAt921W: j i ANALYSIS #1: IRIG NhIL ANALYSIS: ! 1 Ammaytim: 'Ihm frictim ocefficiert between the Im-R-Inc shoe and the guide ! rail is verf hipi, ard the shoes would not kick cver durirq and after impact. !
'Ihe bolts en the guide rail have to absorb all of the energy of the system !
ch:rirq impact. 'Ihis is the est conservatin analysis Wtidt tranmaits maximan I load into the guide rails ar:1. bolting. l Analysis sh: hxmi the tolerance study, the navi== Actuatar pista travel was calo.: lated (3.8"). Using the cleeing time report trtaa Kalsi Engineering, APPDEX A & B of DOCDENT #1523, the time required to travel this distance was derarmined, and the igact velocity was calculated ammaing a ocnstant force sticm. Tw. total system energy is: 1 Um = a V2 2 there as: O a: System mass (IB() . V: Impact velocity (IN/SBC). j 1 Fram the bolting stress test data, the bolt defatund an amount of 18 % of its ! original diamatar before tha failure occarrred , 'Iherefore, the guide rail has I to deform 18% of the bolt diamstar in ceder for the ultimate failuru to cocar. I Frtat the ocnearvaticm of energy law, the impact fcree can he calculate as below: Urotal = 1/2'F (18% of bolt diammtar). All of this energy is ====d to be abenr+md by both of the guide rails, and the bolt load is =====d to be linearly distrikuted as below: O
APRMEX Ct DIFACT CAIDEJEICH P92 2 The umpitude of the ==v4== bolt load (cri me bolt): FBolt = 8/36 Total Bolt load. Fram this load, the marium bolt sheer struss can be alculated as followirg: Ss = F B olt / Ibit root arte. ANADfSIS #2: Frictim coefficient is minima, Imy-R-Inc arm slides m the guide rail and the Gata/Sepant ammambly omtimes to move down ward: Assumpticrt: 1hs guide rail angle is 30', Stallite overlaid to minimize the coefficient of friction. Initially, the valve is installed in the vertical posit 3crt. Fram the waipe cpen positicri, the valve starts to close. The Gata/Sepent and Inv-R-Ice assembly travels dowrnard at the amme velocity. After impact, the Imv-R-Irc shoe and com mechanism rotate, collapsing the gata and segnant. The gate and the Imv-R-Ioc ocritirnas to travel down ward at the same speed. The rotaticri and collapsing of the gata and sepent, in affect slow down the se pent. Sepent velocity calculaticru Vertical velocity of the gate ani Imy-R-Iac: O vy . Imv-R-Ioc shoe,horizcrital velocity: V1 x = Vy Tan (30') . O
l
?
APRMEX Cs IMIRCI CMDRATIN pacg 3 , Due, the sepent vertical final velocity ist vsfinal = K - K 1 Tan (30') / L. sepent deceleraticus is:
* " (Vainitial2-V sfinal 2) / (2 y) leure as:
y: 1he gate and espant travel distance fremt the time the Inv-R-Icck arm shoe to ocritact the guide rail 300 angle to the time the shoe clear this angle. Tue, the force to decelerate the sepent is: F = a a. The faces that slow down the motics) of the segment is created fran the impact between the noving +~- /J and the guide rail, ard this force is aw by the guide rail bolts. Therefore, the ahear strees, cri these bolts can be calculated. (Usin; the triangular distributicr1 lead cri the bolts) N f3: Same as the analysis #1 (Brick wall analysis) but using the bolt test result data. ASST.MPTIW: The spring stiffness of the Inv-R-Ioc arm and guide rail are very W and cmass no dafernatim. Only the spring stiffness of the bolta en ene guide rail is ccrimidered. Using the sprire cxrwtant of the bolt calculated frun ATHNDIX B, Ibit Sisar Stress M: Urotal = K x 2 / 2. i x= % X2 .5 K 1 i l O i I
Page 4 Lou $lANALGPANALYSIS: ANALYSIS FM CLD61NE ilE OF 1.500 SEC. Iniud 5/25/98 CT AMALYSIS FOR 40' I 30' ! 40' 900 IRfCLEAR VALVE ANALYSIS tli MICK WALL ANALYS!$. VALVE NTA: ANALYSIS 63: MICK SALL Aa4 LYSIS US!M THE 80Li TEST NTA PISTON DIA. (!N) 24 A. ASSUMlH TMi ALL SOLIS ABSORMP THE ENEtif EVENLY PIS. AREA (IN'2) = 452.3893 P!S. THICKESS (!N) e I D0li SPf!N6 SilffMESS (LM/IN) 178303 PIS. E IGHT (LIS) = 1024.20$ GAT /SE6 6 LEV. W T.
- 4700
!MPACT WITH ONLi ONE GUIM RAIL:
STEM DIA. (!N) a 4 M r. ON BOLT BY IMPACT (!N) = 0.154109 STER W T. (LIS) = 400 9007 P*ES$URE (PSI) a 1000 IMPACI WITH TWO SUI N RAILSt TOTAL MOY!N6 COMP 0mENTS N T 6124.201 M r. ON DOLT SY IMPACT (lu) 0.!!0385
- 3. ASSUMIN THAT LOAD IISit!BUTED LINEARLY:
MA1. 6AT/SE6 itAVEL (IN) = 3.458 MI. SIM i HD CLEARANCE (!N) = 0.342 IMPACT WiiH ONLY DE GUIN RAIL: M1 PISTON itAVEL DST. (IM)
- 3.1 M r. ON 81 D0li (14) 0.220771 i FROM KALS!'S D0C. I 1523 TRAVEL TIE (SEC) r 0.153 IMPACT WITH TWO SUIN RAILS:
itAVEL VELOCliY (INISEC)
- 41.67320 M r. On il 90Li (IN) : 0.156109 TOTAL ENEt6Y ABSC1 El lf 90LTS:
TO N. ENEt6Y (LIS fil : 1621.468 0!A. (!N) = 0.$07 j i ARIA (IN'2) = 0.201005 i il. Or BOLTS a 2 ) THE ENER6Y IS LINEnttY ABSORM) lY BOTH RAILS, TE RESUlflNG SitESS !$ MYELOPED: ' 1 Or 90t.i CIA. I FAllutt = 11 FORCE On 90LTS (LIS) = 428525.6 MI! MUM FORCE ON BOLT (LM) = 15227.91 MI. DOLT SHEAR SitESS (PSI) s235845.1 ANALYSIS 62: ARM KlCK OVER AS SHM SLIMS ON RAll ANGLE: EI!$i1NEVALV! MOIIFIESVALVE RAIL AN6LI (M6 TEES) a 45 30 SHOE H0t!!. VEL. (IN/SEC) = 41.67320 29.67083 LEV t-LOC ARM LENGTH (lu) = 22.5 22.5 SHOE THICKNESS (!N)
- 3 3 LEV-t LOC EAR LENGTH (!N) = 2.5 2.5 i EAR MLTA VEL. (!N/SEC) 4.869921 2.111650 SE6. VEti. TRAVEL DIST. (IN) = 1.18 1.1 SE6. VERT. ACCEL. (IN/SEC'2) 194.9546 71.42684 SE6 MENT N T. (LPS)
- 2500 2500 )
TOTAL FORCE ON BOLTS (LBS) 15136.23 5545.562 i MllMUM FCtCE On DOLT (LIS) = 3363.607 1232.347 l MAI. SOLT SHEAR STRESS (PSI) s8330.470 i 3052.001 -
- O i i
Pade 5 L(Ris!AmA LLP ANAlfSIS: ANALYS!$ FOR CLOSING f!ME OF 3.001 SEC. tol ud 5/25/06
.I ARALYS15 FOR 40' I 30' I 40' 900 NUCLEAR VALW AmALTSIS lit 981C1 WALL ANALYSIS.
VALVE DATA: ANALYS1$ 63: MICK WALL AMLTSIS US!M i)E BOLT TEST BATA Plsf0N 914. (!N)
- 24 Pl$. AM A (!N'2) a A. ASSUMI6 THAT ALL 80Lis ASSORMD THE EIOGY EVENLY 452.3093 P!S. THICKNESS (lu) : I D0LT SPt!NG SilFFNESS (LIS/IN) 170303 P!S. WE16HT (LIS)
- 1024.201 6AT/SE6 6 LEV. W6T. 4700 IWACT WITH ONLY ONE GUIM RA!L:
STEM DIA. (lN)
- 4 M r. ON D0LT SY IMPACT (IN) s 0.004100 STEM W6T. (LIS) 400 30lf PtES$Utt (PSI) 1000 IMPACT WifH TWO GUI N RA!LS:
TOTAL MOVlll6 COMPONENTS W6i e 6124.201 M r. ON D0LT If IMPACT (lu) = 0.059464
- 9. ASSUMING THAT LOAD IISTRlluTED LINEARLT:
MI. 6AT/SES TRAVEL (!N) 3.450 Mt. STM i HD CLEARANCE (!N) 0.342
!MPACT WITH ONLY ONE GUIN RAIL:
M1. Pl$f0N TRAVEL DST. (lN) = 3.1 M r. ON il 80l.T (IN)
- 0.118136 ft0M LALS!'S 000. I 1523 TRAVil TIME (SEC) 0.294 IMPACT W!iH TWO SUI M RAILS:
itAVEL VELOClif (!N/SEC) = 26.76054 Mr. ON 81 DOLI (!N) = 0.084100 TOTAL ENER6Y ASSORMD BY SOLTS: 10m. ENER6Y !LIS FT) 4 72.9241 T #!A. (!N) = 0.507 diAREA(IN'2)= 0.291985 O. OF 80LTS = 2 THE ENEt61 !$ LINEnttf ASSORMI If DOTH RAILS, THE RESUlilNG SitESS IS MVELOPED:
$ OF 30LT I!A. I FA! LURE : II FORCE ON 90LTS (LIS) = 124372.0 MIIMUM F0tCE ON BOLT (Lis) = 27631.24 Mt. B0li SHEAR Sit!$S (PSI) s58450.11 ANALYSIS 12: ARM t!CK OVER Al$ SHE SLIMS ON RA!L ANGLE:
EllSf!NGVALVE M0l!FIEIVALVE RAIL A14LE (DE6tEIS) : 45 30 SHOE H0t!!. VEL. (INISEC) = 26.76056 15.45021 LIV-R LOC ARM LEN6TH (!N) = 22.5 22.5 SHOE THICENESS (!N) = 3 3 LIV-t-LOC EAR LEN6TH (!N) = 2.5 2.5 EAR DELTA VEL. (!NISEC) = 2.623584 1.514727 SE6. VERT. TRAVEL tSt. (!N) = 1.10 1.9 SE6 VERT. ACCEL. (14/SEC'2) 856.58220 20.73031 SE6 MENT W67. (LIS) 2500 2500 T0fAL FORCE ON BOLTS (Lis) 4313.028 1609.502 MI! MUM F0tCE CN IOLT (LIS) = 976.22S5 357.6673 MI SOLI SHEAR SitESS (PSI) s2417.774 385.8159 b v
Page 6 LOUSIANA L6P ANALYSIS: ANALYSIS FOR CLOSING flE OF 5.945 SEC. Revised 5/25/00
.i ANALYSIS f0t 40' I 30' I 40' 900 NUCLEAR VALVE ANALYSIS 41: tilCK ult ANALYSIS.
ANALYSIS 13: IllCI WALL ANALYSl$ USING TE 80Li TEST DATA VALVE DATA: PISTON DIA. (IN) = 24 A. ASSUMING TMi ALL 80LIS A850tKD TE ENER6Y EVEls.Y: PIS. AREA (IN'2) a 452.3893 PlS. THICKNESS (IN) = 8 90Li SPRING SilffMSS (LSS/IN) 170303 P!l.WE16Hi(LIS)= 1024.209 C i/SE6 6 LEV. WI. = 4700 IMPACI WliH ONLY ONE Sul K TAIL: STEM DlA. IlN) = 4 Kr. ON B0li BY IWACT (IN) = 0.042273 STEM W61. (LIS) 400 10DY PRES $Utt (PSI) 1000 IMPACT WITH TWO Gul K RAILS: TOTAL Movin6 COMPONENi$ Wi a 6124.209 Kr. ON 90Li SY IWACT IIN)
- 0.029892
- 8. ASSUMING THAT LOAD Bllit!BUTED LINEARLY:
M1. 6AT/SE6 TRAVEL (!N) 3.458 MI. STM i HD CLEARANCE (lu) = 0.342 IMPACT WlfH ONLY ONE GUlK RAIL: u !. P!SION ftAVEL DST. (14) = 3.8 Kr. ON 8130Li (IN) = 0.059784 ft0M KALS!'S D00. I 1523 itAVEL TIRE (SEC) = 0.565 IMPACT W!iH TWO 6UlK RAILE TRAVEL VELOCITY (IN/SEC) = 13.45132 Kr. ON 1150LT (!N) = 0.042273 TOTAL ENER6Y A350t K D BY SOLTS: T0 N. ENEf6Y (LIS FT) a 119.4901 O DIA. (lu) = 0.507 Q i AREA (!N'2) = 0.201885 NO. OF 30LTS a 2 THE ENER6Y IS LINEARLY ADS 0tKB BY DOTH RAILS, THE RESUlilNG sites $ l$ KVELOPED: 1 Of DOLT DIA. I FA!LUtt = 18 FORCE ON BOLTS (LIS) = 31424.09 , MI! MUM f0tCE ON BOLT (LIS) = 6983.131 MI. 00Li SHEAR SitESS (PSI) =17294.75 ANALYSIS 12: ARM K!CK OVER Al(D SHOE SLINS ON TAIL ANGLEt ' EllSilN6 VALVE MODIFIED Vt1YE TAIL AN6LE (K 6 TEES) = 45 30 SHOE H0t!Z. VEL. (IN/SEC) 13.45132 7.766127 LEV-t LOC ARM LEN6TH (lu) = 22.5 22.5 SHOE THICKNESS (!N)
- 3 3 LEV R-LOC EAR LEdiTH (!N) = 2.5 2.5 '
EAR DELTA VEL. (IN/SEC) 1.318757 0.761385 SEG. VEti. TRAVEL DIST. (!N) = 1.18 1.9 i SE6. VEti. ACCEL. (IN/SEC'2) 814.29616 5.237782 SE6 MENT W67. (1.35) = 2500 2500 TOTAL FORCE CN IOLIS (LIS) : 1109.951 406.6601 MA!! MUM FCRCE ON BOLT (LBS) 246.6557 90.36891 MI. BOLT SHEAR SitESS (PSI) e610.8794 223.8119 O
-_-a .-. ,- a m a--- .m- s., _. a,.a-amms.Asm...saa.ma 4a w ama e4. s.aa m a __.sa A ,c A .o - J -
e d i I l 4 1 E.R. 7834 E.O. 25504-001 , LN D i i 4 t d 1 i i l 1 1 4 i i
i Page 1 F r O i se Please deliver this fax message to: Name: Mr.TriLe ! Phone: l Firma.ocation: WKM From : P. Daniel Akvez Inc 9 KolsiEngineering,478 SugorLand.TX 77 ! Phone No: 713/2406500 - o Date: April 29,1988 ! 4/W- s 2/ 3 Telecepter Telephone: 713 240-0255 VertAcationNo. 713 240 4 500 Fax Model: Cannon 220 Automatic or Manual KALSI ENGINEERING, INC.
..-m.6 ... . . ...
~~
y Page 2 p()--- ocooooooooooooooosooooooooeosooooooooooooooooooooooooossessee< W e [ TRAVEL YERSUS TIME AND TOTAL EXITING FLOW RATE
-- Toru. r ioT0N mver . . . . . . r. . . - . :- . c. . . . . . . 3 r 2 50 VALVE I NT ERNAL P R E88UR E . . . . . . . . . . . . . . . . . . . . . . 108 5. O
' NITROGEN PRESSURE (OPEN Pos! TION). . . . . . . . . . . . . . 2073. 0
. --"-' ~ -~ F YR hvg 6 409 1 t.r r e.n A T u n g , pFOREES F .....~~T.'.7..
- 5'
) FYR0VCL 100 WE!GHT DENS!TY (L5S/CUSIC FOOT) .... 73.98 FYROVEL 100 VISCOSITY (CENT! STOKES) ........... 5000.O NUMBER gF MYpn AVLIG EK I Tu . . ................... ' !~ ' ' ' ' '
> I g
~
_ ..L?*_'_...* . 3m _e.9. e W= .
*** NOMENCLATURE *** l L1 = PISTOR 7057TTVN" FRDM FUL1"0 PEN" ""-- ~~ " ~~
, g TIME = CLAP 8ED 7!ME DURING 7 RAVEL Q = TOTAL FLOW RATE j
-~-""
PRESS. TOP'~=~'RITROCEN PRESSURE'A30VE THE P!5 TOR-~ ~ g PRESS. SOT = HYDRUALIC FLUID PRESSURE BELOW THE PISTON P-FORCE = N!TROCEN PRESSURE FORCE R-FORCE'~a- TOTAI' REEIETANCE FORCm ~ I L1 TIME Q PRESS. TOP PRESS. BOT P-FORCE I NC HES -~~~'SEc -'R-FORCIi GP K' """-~- *P810' ~~ ~ ~ ~ P S ! s CB S ' ' L88 - l g 0.00 C.000 1600,0 2073.0 2056.4 937803. 0.20 937703.; 0.014 1590.0 2055.0 2036,3 929680. 929440 ' O 40 O' "-- O.60 0,80 0 U29'~~ "T5eo. o C.043 0, 038 1570.0 1562.5 ao37. a 2039.9 2002,7 a029. n 2003.0 1985.7
=
92 T675~" '- 913788. 904013. 921575 913688 905913 1.00' oom i m35. '5 * ~198mi w '1968~E-~'-" 595354'-" 898254 g l 1.20 0,087 1548.5 1969.I 1951.8 890001. 890701 1.40 0.102 1042.0 1952.6 1935.2 883357, 883257. i 1.60'~~0 11r '1535: v 193o g t vilrr--- 874019. 875919.: g 1.80 0. 131 1528. 5 1920,4 1902.8 568781. 868481 2.00 0.146 1021. 5 1904.7 1886.9 861648. 861548 l 2.20 0. r61 T 515.~ 0-~ ~~'1899. 4 1971 .s --' 554F12.
) 2.40 2.60 0.176 C.193 1508.5 1873.8 1855.8 847672.
' ' 8 5 4 5 1 2 847572 1502.0 1858.6 1840.& 840828. 840729
" - "" 2. 8 0 0.207- a495.5 1843.7 "1895.'6" g 'J.00 834078.-
- 833978 0.222 1489.0 1929.0 1910.O B27420.
3.20 C.237 827320 1483.0 1814.5 1796.2 820852. 920752 3 40~ 0. 2 53 ' -- T4 t o . s g 3.60 0.268
'**1000.2 "1781; 7~ ' 314373: 814273 1470.5 1786.0 1767.5 807978. 807878 3.80 0.204 1464.5 1772.1 1753.5 001670.
4"00- 0:299 801570 1458.15 27a6. .s '1739.e 795447.--
) 4.20 4.40 0.315
- 0. 331 1452.5 1744.7 1726.0 789301, 795347 789201 1446.5 1731.3 1712.5 783240, 783140
C."6 0 '" 0-'3 9 f 144v. o a t iv. i 1699/ R * ---- '77723e.
g 4.00 0.363 '- 777136 1434.5 1705.1 1686.0 771348. 771248 5.00 0.378 2429.0 1692.2 1673.0 765515. 765415
'3.20'-~0 394- 1423.v ~~ 1679"4 -- --' 166072 759757.- 759657 5.40 0.411 1417.5 1666.9 1647.6 5.60 0.427 754075. 753975 1412.0 1654.5 1635.1 748462. 748362 5.80 0. 4 4 3 - -- T4 0'6 0-*
- 1642'2-"~ ~ 1622,8' '
g 6.00 0.459 742922." 742822 1400.5 1630.1 1610.6 737448. 737348 6.20 0.47L 1395.0 1618.2 1598.5 732045. 6 40 0 490 731945 1389.5 1606. 4 "' -- 1586.7- - 726709. 726609 I
(. o coo o ooo oo s s oo o o oooo o o ooo s e ooooos s e oce n e s co c oooc"eVS obooo ooo t ooe e s g TRAVEL VERSUS TIME AND TOTAL EXITING FLOW RATE TOnc nsv0rvRwEr n . . : . . . . r. . . . . . .r.r. . . . . . 3i . 250" -- VALVE I N1 ER NAL P R E SSUR E . . . . . . . . . . . . . . . . . . . . . . . 108 5. O
" ' " " NITROCEN PRESSURE (OPEN PDS!T!ON). . . . . . . . . . . . . . 2073. O FYGQUEC~T50 TEPPENATORE-" DEGREES F . . . . . .". . . . '. . l " ' '-"5
) FYROV8tL 100 WE!9HT DENSITY (LIS/CUDIC FOOT). . . . . 73.95 rYROVEL 150 v!sCOstTY (CENT sTOxE5: ........... 5000.O i
'--" ~' ~ NUMB ER 'OFRYDMXUCIC EX175 . . . . ~. 7. . . . . l . .~.TI. 7 : ' ~" 1
..E--.5,k f . &
) *** NOMENCLATURE *e*
g L1 = PISTOR7D5!TIOFFRDWFVLt. OPEN"~- - - ~ ~ ~ TIME a ELAPSED TIME DURING TRAVEL 0 = TOTAL FLOW RATE g PRESS. TOP = N!TROCEN PRE'55URE' ABOVE TM PISTON PRESS. BOT = HYDRUALIC FLUID PRE 58URE BELOW THE PISTON 2 P-FORCE = N!TROGEN PRES 8URE FORCE l R-FORCE = TOTAE' RESISTANCE FORCE-~~" ' '"" -~-~~~ "' l D L1 TIME Q PRESS. TOP PRESS. SOT P-FORCE 1-FORC i INCHES' -"5EC~ ' OPM -~PSID - PSIG"- * ' LE S -- " - ' g O.00 000. 0 LSS 0.000 2073.0 2056,4 937803. 937703 ' O.20 C.029 796.5 2055.0 2038,3 0'. 4 0' 929680. 929580 g 0; b f 793.0 '2037,a 2020l5' 921475:*- 921575 , 0.60 0. 086 789.5 2019.9 0.80 2003.0 913785. 913685 0.115 0- *
- 1. 00' ' O. 144 -
- 1. 20 756.0 752 5 2002.7 1985T--- '
1995.7 1965"6 906013. 595354. 905913 898254 5 C.173 779.0 1969.I 1951.8 1.40 C.203 890801. 890701 775. 5 1952.6 1935,2 303357.
- 1. 60-- ' 0~.' 2 32 ~ ~ 772.O aV30. g 383257 g 1.80 0.262 IViB. v u76019. 875919 2.00 769.0 1920.4 1V02, 8 868781. 869681 0, 291 765.5 1904,7 1 sS6. , e6164s. e6154s 2.20 '0; 321 762 3 g 2.40 1989. a
- 197a. a 854612.'" 854512 C. 351 759. 0 1873.8 2.60 1855.3 R47672. 947572 :
C. 381 756. 0 1958.6 1940.6 840828. 840728 i g 2. 3.0000"- ' C.442 O. 411- 752.~r-- 749.5
~1943. 7 --~ -'" 1825. 4 "" ~-" 334 073-- ---'- 833978 3.20 1829.0 1910.8 827420. 827320 C.472 746.5 1814.5 1796.2 3.40 0. 503 "--"743. 5 --" 1800, a 820852. 820752 !
g 3.60 1731' 7--- - 314373. 814273 l 0, 534 740.5 1786.0 1767.5 807978. 3.80 C. 565 737,5 1772.1 1753.5 807875 : 4.00 - 0. 596 901670. 801570 g 734:5 1755 3 - 1739.6- - 795447. 4.20 C.627 731.5 1744.7 1726.0 759301, 795347 l 4.40 0.658 728.5 789201 !
- 4. 60'" 0789'-' " 725. 5 1731.3 1712.5 783240. 783140 p -1711:1- 1699;2 i77256. " 777156 !
, 4.80 0.721 722.5 1705.1 5.00 0. 752 1656.0 771348. 771248 ' 720.0 1692.2 1673.0 765515. 765415 5.20- 0.704 717'. U- 1679T4-p 1660,2 759757; - 759657 5.40 C.816 714.0 . 1666.9 1647,6 754075. 753975 '
- 5. 60 0.B48 711.5 1654.5 1635.1 743462. 748362 5 00 - O.BBO-'
f 708,5 *'1642.2 ~ "" 1622,8- ' g 6 00 0.912 742922. 742622 6.20 706.0 1630.1 1610,6 737448, 737348 0.945 703.5 1618.2 1598.5 732045. 6.40 0.977' 700.5 " 1606; 4- 731945 : 1586.7' 726709, 726609 ; I I l
DOCUMENT No. 1523 f%DEXKFxe Page 4 O . **++++++++ ** **+++ ; ; ; ; ; ; ; ; ; ; ; *+++* 4 ****** *** e e e ; ; ; ** TRAvst VERSUS TIME AND TOTAL EXITING FIM RATE TOTAL PISTON TRAVEL ........................... 31.250 VALVE INTERNAL PRES SURE . . . . . . . . . . . . . . . . . . . . . . . 108 5. 0 MITROCEN PRESSURE (OPEN P051710N) . . . . . . . . . . . . . . 2073.0 FYRQUEL 150 TEMPERATURE, DECREES F ............. 5 WRQUEL 150 WEIGHT DENSITY (LSS/ CUBIC POOT) . . . . 73.98 FYRQUEL 150 VISCOSITY (CENTISTOKES) ........... 5000.0 NUMBEA 0F HYDRAULIC EXITS ...................... 1
*** NOMENCIATUU ***
L1 - PISTON POSITION nt0M FULL OPEN TINE = EIAPSED TINE DURING TRAVEL Q = TOTAL FLOW RAff. PRESS. TOP - NITROCEN PRESSURE ABOVE THE PISTON PRESS.80T - HYDRUALIC FLUID PRESSURE SEIN THE PISTON P. FORCE = NITROCEN PRESSURE FORCE R. FORCE = TOTAL RESISTANCE FORCE L1 TIME O INCHES 0.00 SEC 0.000 Q CPM 2956.8 PRESS. TOP PSIC 2073.0 PRESS.8OT PSIC 2056.4 P. FORCE LSS 937803. R. FORCE LBS - 0.20 0.008 2943.9 937703. 2055.0 2038.3 929680. 0.40 0.015 2931.2 929580. 2037.3 2020.5 921675. 0.60 0.023 2918.7 921575. 2019.9 2003.0 913788. 0.80 0.031 2906.2 913688. 2002.7 1985.7 906013. 905913. 1.00 0.039 2893.9 1985.8 1968.6 898354 898254 1.20 0.047 2881.7 1969.1 1951.8 1.40 890801. 890701, 0.055 2869.7 1952.6 1935.2 1.60 883357. 883257 0.063 2857.7 1936.4 1918.9 876019. 1.80 0.071 2845.9 875919. 1920.4 1902.8 866781. 868681, 2.00 0.079 2834.2 1904.7 1886.9 2.20 861648. 861548, 0.087 2822.6 1889.1 1871.3 2.40 854612. 854512. 0.095 2811.1 1873.8 1855.8 847672 2.60 0.103 2799.7 847572. 1858.6 1840.6 840828, 840728, 2.80 0.111 2788.5 1843.7 1825.6 3.00 834078. 833978 0.119 2777.3 1829.0 1810.8 3.20 827420. 827320. 0.128 2766.3 1814.5 1796.2 820852, 3.40 820752, 0.136 2755.3 1800.2 1781.7 3.60 814373. 814273. 0.144 2744.5 1786.0 1767.5 3.80 807978. 807878. 0.153, 2733.8 1772.1 1753.5 4.00 801670. 801570. 0.161 2723.1 1758.3 1739.6 795447, 795347, 4.20 0.169 2712.6 1744.7 1726.0 789301, 4.40 789201, 0.178 2702.1 1731.3 1712.5 783240, 783140. O M Atal ENGINEERING, INC.
+ = = c. . ~ ,. -
I l l _ _ _ _
._. . _ . . _ _ _ _ - - _ _ - - - - - - - - - - - - - - - - - ~
m -_*m.-e..an- aem um-s,m su_-m-m.m.w, a--,mm-m a . -- - -w a a s. e amr._a . eam u-- m-ma . maamm-u-- m.ean m m ,a m sa --a 'waus_ a m m=-uem- u - --
. ea Y
e l l l l r I I t f I l i 4 i i s i f l t e I j i i ! 1 I l l a j j E.R. 7834 t i E.O. 244M@l - A i g! 4 BX2 SI3EES M9Cf5IS - : i e 1 t l
- I i
4 1 4 9 J 1 i } 1 i i I l 4 J i l l l 1 4 i i i i i 1
, , , , , ,_,-,-.-wwy.ww---ei-N w"N"'WM'"~ ' "' '
l Page 1 APPENDIX E BOLT SIRESS CREMED Ft MISAIJG4ENf MO PitEIDAD. mim M AND M3ENT CAfNIATICHit Referunome:
- 1. PGOUI.AS KR 3IRESS MO SIRAIN by R. J. Ibark. 4th. Riitim. Page 106, came 9.
- 2. MEQ9NICAL DCINEERING IESICM by J. E. Shigley. Page 247.
1 J v 1 l -= =-J l . l . + l l I V ASSGGTIG( Durirsy the installation instro of the seat skirts bolta, the bolts are paloadni to 150 FT-IBS tonps. h the bolt is fully pnloaded, it is ==* that surfaos. the canical flat head of thu bolt is coupletely in ccritact with cardcal In the event that the anting bolt holes of the guide rail ard the seat skirt are l mi-tched by an amourit of d irstes, the bolt total length would have to abaoth i an additicrial banding streme cmated by this mimmatcts. 1 MOLYSIS:
'Iha bolt abamte the misantcts under a form of banding nu:mont applied at the mean I diameter of the ocnical head.1his barding nament is the maant to cause 2n axial deformaticr1 equal to the amount of al-td).
Fna PGMJIAS KR SIRESS AND SIRAIN by Roark, 4th. Riition, page 106, case 9:
- O
APPIMDIX Et BOI2 S'IRESS A% LYSIS PAGE 2. ML 2 I
.; a 2EI Itars as:
y: bolt o % mi-tch. l M: barx*
- wit.
L: bol E: Yc - - m of Elasticity. I: Bc. -
- Inertia.
Thus: 2 y s. . M= L2 BOLT KRIE CAYUJIATICN: (. s . w ec O " '
.N
% w' #
- di'~
/ } A p* !
I I
.719' 1
I l l h ,O ! MATiAW ?LA N OF "TME l l l l GVi OP.L P. AIL /L*JD ~u4f - f.6 h 6eler l l l l i I, i l C
=e-- D 4 l O
APRNDIX Et BOLT FIRESS CAIMATICH. PAGE 3. Mcznant about point C: Mc = 1.5 Fx + m Fy / 2 m = D + 2
- H / 2N (490)
Blus, - M: = Fm 1.5 SIN (490) + 2 CDS (490) / 2 Let 0 K = 1.5 SIN (490) + 2 CDS (49 )/2 M=Mc Fm =M/K Bolt preload calculaticn:
Reference:
MD3RNICAL DCINEERING IESI@ By Shigley. 3rd. Biition. Page 247. T = .2 Fp d itars as: T = Bolt preload tortpe. Fp = Bolt Fettse. d = Bolt mean diamatar. Note: 'Iha ocefficient of fricticzi of the thread and collar utill-ed is .15. Q Fp = T / (.2
- d) str===== calm 1=eim:
Point A Bending acaent at a: Ma = .324 Fm SIN (490) + 2 Fm 006 (490) / 2 Bending stress: Ma D sb = 2I PI 04 1= 64 Tensicnal stress: (Fm
- CDS (490) + fp) 4 St =
PI D2 O
APR!NDIX T' !!OLT S'IRESS M0GSIS PAGE 4. Shear stress: 4 Fm SIN (490) Se = i PI D2 ' l Stress Intensity: l
- _ 1 SI = ((Sb + St) / 2)2 + ss2 _
2
)
i Point B:
'Ihe calculaticos of point B are the.sman as point A with the excepticn of the BendixJ Manant at point B:
Bending nrmurit at B j 0 7t = .719 Fm SIN (49 ) + [h Fm 006 (490) / 2
'Ihe calculaticn nasult are attached in the following table. 'Ihe calculatico result in the following table shows that scue of the Stress Intensities of the bolts are evnaamive. However, these str- are the constant stra=ama aglied to the bolt at pruload, and any permanent deformaticns resultad '
by these stresses would not fall the bolts. O ! i b [ i i i [ i i I r i O i I I , r 1 . . _ . . . . _ - - _ .---- -. - .- -
Page 5 O l
? Po 8
.0094 2 g(
l O O-3 ' !
.0132 l
, .0051 i
-O O t 4 13 C '
.0241 J 5 7
f 14 .0101 0342 3 t 6 i O N 15 o i I 7 16 O O- -- a ' 87
.0282 '0050 g 0 i IS 1
1 I B/M 247093 S/N 506158 "B" VALVE E.O. 25504-001 E.R. 7834 O
1 Page 6 I
- t. 8. 255N401 E. R. 78H 14Lfills CALCEAflu W RT ITIES$ M TO M INSTALLAf!p RISALIGIBUT OF M TW RATING 10LT MOLES:
i VALVE R 124 I (At Missouri City Plant)
Reference:
FORMULAS Mt $7tESS AND STRAIN by R. J. teart. 4th Edittaa, page IM case 9. y : Total aisaligneent of bolt holes. 0 Solt liaseter. ! L = bolt effective length. Ih a Bolt head dieseter. E = 30,000,'000 PSI. l F : Bolt testional force. ' 1 a telt esotat of inertia. A = lolt area. M : Sending moetet. T = lolt preload torque. Sb = leadieg stress. Fe Bending lead. St a tenstle stress. Fp = Bolt preleed Ss a Shear stress
$1 Stress latensity.
y (lN) L (lu) 0.005 1.5 0.0058 1.5 0.0094 0.0101 0.0132 0.0241 0.0262 0.0342 1.5 1.5 1.5 1.5 9(!N) 1.5 1.5 0.507 0.507 0.507 0.507 0.507 0.507 0.507 9.507 A (lit'2) I 4 ) 0.201885 0.201985 0.201985 0.201985 0.201085 0.201885 0.261005 0.201185 0.003243 0.003243 0.003243 0.M3243 0.003243 0.M3243 0.M3243 0.003243 Q%(IR) . JS) 36.03787 41.00394 67.75121 72.79651 95.14000 173.1925 108.8304 246.4990 Fa (LBS) 1.0702971.0702971.0702971.0702971.0702971.0702971.0702971.070297 T (FT-LDS) 291.15057D 338.2301 548.1661 500.9069 769.1651 1405.404 1527.067 1994.391 150 !!0 150 !% 150 150 rp (LDS) 150 F Total (L3S) 17751. 47 17751. 47 17751. 47 17751. 47 17751. 47 ( U51. 47 17751. 47 ( U51. 47 17942.77 17973.37 18111.10 18137.00 18256.49 19673.50 19753.05 19059.91 R at A (FT-LBS)l4.4723416,7879127.20000 29.23413 30.2M90 69.75669 75.83507 98.99082 St at A (PSI) St at A (PSI) 13573.63 15745.42 25518.44 27418.75 35834.40 65424.94 71125.87 92643.69 St at A (PSI) 88875.84 89027.44 99709.66 89642.31 90429.78 92495.39 92893.35 94409.39
$1 at A (PSI) 1090.004 1264.405 2049.200 2201.909 2877.612 5253.822 5711.624 7455.632 102472. 6 I H803. 3 115300. 9 117343. 7 126395. 2 15t269. 5 iG4416. 5 187945.8 R
56 at at II(PSI) (FT tts)21.71586 25.19H0 40.82583 43.96605 57.32969 IM.67N 113.7911148.5365 St at I (PSI) 20367.35 23626.13 38290.63 4tl42.M 53769.82 90170.66 IM724.9139312.7 Ss at I (PSI) 90675.84 99027.44 99709.66 39042.31 90429.78 92495.39 92993.35 94409.39 Si at I (PSI) 1090.0041264.445 2049.200 2201.009 28U.612 5253.t22 5711.624 7455.632 109264.9 112601.9 129%5. 0 131054. 3 144314. 4 1909$5. 3 199944. 0234197. 3 O 1
Vi . :.:'.*:-% ,h ; .) c.\ ' : , . . , ,- .; _ .s P' age 7 [.;.(Q';, p jPjj ] l, 8 j p} w - O1 a . .. .. ggy l 11 1 gj;1
!!!'= a= = a ?!NHj MW J m. ..m. . m,,, m. . . u.d. r 1
= .
'q 111 i i,
MM
,, ;. . ;. c r
l je! } us7 lil !!!!!!!!!!!!H t 1 - I< @:w.o
\
p .N.
- f..N. ...h ... .k g,7 'f l,~,'-.- [
g]},f
, , 33 _,, y p oemm cv.,
i ;}j 3 i _ i.n. .in.
. . .en... m. . n. . 3, . . i 4 m 3
I E f g i y yp I g'2;j}Jp 5 g 8,g#7;,$g _j m.!! 1.:.1. su.. tu. n.. 3
=
' ... m... u..g ..m.. n.. j.c1.,H.i ,,a,rk
! I jp j I,N, I!,! Hi in U l Oi K!ME 7 . .. ... ... ..
j'!{J}lfg.4 gg.g.7 3 lu.......,=*==g,g,;};,lj yg pg; :. n n w Qig; 1 r%n. d @ Q W; w s D !!!!!!!!!!!!!!!!!!!!!! ,j]jJs.p1j,)
@I 3.$II y11.t- p~pg a $. 11 j .,
- m. .z un au ,u, u,= = ,lj nI,! %4"m v.n x m. w.W w -
i
,E j,q =
} D5 pa ,!,}!
7 .'i. a$$ m _ i 1 m. ...i .sm.. am an r1l i l j-]. .u.s.rj), k.gdM
! ])ji .
0 b, Irl 8,O. .,L. ) n
- m. . .e r. .t.u. .n u. . .n m.
. . .. s. .
,, y.x
, i r a. . n. .n. .u.m. . . u. . .n 5: n .n. s. .
i <- w e- -- Q g } 8
}, n mei we- ~~
,g 4 M. . ..f1. H..R.t .u.. M. . . H. 25 3 I. H. 1 8 5
. H.. a z- 7- _d l . . _s 9 3g i
_J.; a jj y,} s 3g ' m... a rin. n...n. .i.in..J a..n
,u)3 u J, i l __==/;lD, i I
, y 1..H..i!5H..
. . . . . .il.!t i.n.fi..l!I !!
gg*;g,IT i g 1
) ...-..au==.uu3lgj!g;j l
"wm . --
-_L-_--
. W6 -
O l l l
\
E.R. 7834 E.O. 25504-001 l APPENDIX F l N ANMESIS REPCRT O
i
- Page 1 FLOW CONTR0' O
t 55=~ METALLURGICAL REPORT c100583 E A' 7/4' o TO: E.O. 25504 002 FROM: Ray Voelkel Materials Development
SUBJECT:
Failure Analysis of the 40'x30' Class 900 Nuclear Gate Valve for Louisiana Power and Light DATE: May 13,1988 i INTRODUCTION: During a recent outage of the Louisiana Power and Light (LP&L) Waterford m3 nuclear power plant, inspection of a turbine steam trap revealed a piece of the 40'x30' Class 900 Main Steam Isolatation Valve (MSIV) sate skirt rail and several heads from failed flat head bolts. The pieces of valve parts i were associated with the valve identified as MS124B when the valve was disassembled and the obvious parts were missing. An on site examination was made by LPAL finding both guide rails from the < gate seat skirt had separated from the plate of the skirt. One rail was O,' severely bent and was found in the bottom of the valve. The second rail was broken into two pieces and was found in the turbine steam trap. The segment skirt guide rails were still attached, but both rails were missing several bolt heads. A further description of the condition of the returned parts at the Flow Control. W K M Plant, is found in Engineering Report #7834 which describes the mechanical functioning of the valve and possible contributing causes for the skirt bolt failures. This Metallurgical Report, while overlapping in some areas with the Engineering Report, will be focused on the bolts used for attaching the guide rails to the skirt plate and the cause of failure. CONCLUSIONS: 1. Ultimate failure of all of the bolts examined in the as received condition was due to fracture by shear.
- 2. Chemical analysis indicated that bolt material was ASTM A574 (AISI 4130). One of the bolts checked for chemistry was carbon steel, AISI 1040.
5 P O Box 2117 Houston. Texas 77252 2117 (713)499 8511 Te4x 166282 DEMCO*
- LAAKIN*
- THORNHILL CRAVER
- W K.V8 e WHEEUNG MACHINE
- PRODUCTS
MR.100538 MAY 13,1988
- E.O. 25504 002 PAGE 2 l 3. All bolts exam!aed experienced some metal loss in the form of pitting I corrosion. Some bolts were more corroded than others, j
- 4. Bimetallic coupling resulted in galvanic corrosion cells forming at the two interfaces of the 17-4PH material and the low alloy steel bolts. ,
t
- 5. The cross section of the bolts was reduced by initial cracking due to corrosion fatigue.
- 6. No evidence was found to indicate the presence of flaws in the bolts when they were installed.
- 7. The bolts were subjected to complex stresses. One indication of overtorquing was found as well as indlation of misalignment of bolt holes, plus mechanical induced stress.
- 8. Bolts were manufactured in accordance with ASTM A574 and had forged heads and rolled threads.
- 9. The material hardness of all bolts tested, were within the specified ASTM A574 hardness requirements.
RECOMMENDATIONS:
- 1. Seat skirts should be manufactured with matching parts to eliminate misalignment of bolt holes.
- 2. Bolting material should match the chemistry of the seat, guide rails and seat skirt to avoid galvanic corrosion and climinating susceptibility to corrosion fatigue.
DISCUSSION: The returned parts from LP&L which were the subject of this investigation are shown in Appendix A of this report.
)
Pictures show the two rails; one bent and broken and the second one bent l I only. The broken rail will be referred to as the right (R) rail and the I bent rail will be referred to as the left (L) rail throughout this report. ' Also shown is the gate skirt plate minus the rails and the segment seat skirt with the rails intact. Close up pictures of the bolts in the segment skirt show indications of misalignment with tilted bolt heads and varying clearances between one side of the bolt head from the other. This misalignment could cause the bolts to be overtorqued during assembly and resulting in complex static loading. The second set of pictures in. Appendix B are of the remaining fractured bolts in the two rails which separated from the gate seat skirt. Bolts O #4R, #8R, and #9R were removed by LP&L for their investigation. Bolt #6R was lost after the rail fractured into two pieces.
M.R. 100388 - kiAY 13,1983 EO. 25304 002 PAGE 3 Close examination of these remaining bolts ladicate that the dynamic loading or shear force was generally from the same direction. The point of fracture origination la several of the bolts ladicate that a resultant { t force influenced by the preloading caused an off line shear force to the bolt. For the metallurgical investigation, the following bolts were chosen for examination:
- 1. Bolts #2R #3R, #7L, #8L, and #1, #3 (segment skirt) were used for chemical analysis.
- 2. Bolts #1, #2, and #3 examined by Scanning Electron, Microscope (SEM).
Bolts #1 and #3 broke when an attempt was made to remove them from the segment skirt.
- 3. Bolt #2 (sheared in laboratory test), #2R, and #3R were examined by optical microscope.
- 4. Bolt #5 was used for the macroctching examination.
Chemical analyses were made on six bolts. The results are listed in Table i of Appendix C. The chemistry of five of the bolts indicated that they were made from an AISI Grade 4130 steel This type of alloy steel socket-head cap screw would have been manufactured according to ASTM Standard A574. The sixth bolt, #2R, was made from an AISI Grade 1040 carbon steel. The fractured surfaces from bolts #1, #2, and #3 were examined with a Scanning Electron Microscope. The three bolts are from the segment seat skirt with the guide rails still intact. Bolt #1 (head only) is shown in Figure 1, Appendix C. Bolt #2 is shown in Figures 2 and 3, and bolt #3 is l shown in Figures 4 and 5. Bolts #1 and #3 were partially cracked and failed during the attempt to remove them. Bolt #2 was removed complete and used for shear testing in the laboratory. Before the shear testing, this bolt was wet magnafluxed and dye penetrant inspected and showed no indication of defects. After the shear test, however, a small thumbnail precrack was noticed at the edge of the fractured surface in the root of the thread. l Visual examination of the bolt head, Figure 1, shows a primary corrosion fatigue crack originating at corrosion pits in the thread root. Two secondary cracks on either side of the main crack also originated it corrosion pits. The three cracks propagated until they met to form a single larger crack forming a visible band. This band is where the crack propagation was first arrested followed by slow growth until a high stress caused rapid propagation to a point when it was sheared off during removal. Crack growth rate obviously varied widely depending on the variations in stress factors such as stress state, stress intensity range and stress wave shape and frequency, and in addition to varying as the result of environmental effects. O
l l M.R. 1005ss MAY 13,1933 E.O. 25504402 PAGE 4 An SEM scan over the uncleaned surface showed heavy oxide layer containing 'O primarily iron. After cleaning the surface, the SEM scan shows in Figure 6 at 35X, the primary crack origin at an extremely corroded surface area. The fracture surface in all areas was effected by the corrosion and left little or no evidence of crack propagation mode. Figure 7 at 50X shows the band area where the three cracks came together. Fatigue striations are not visible because of the hostility of the corroding environment. Bolt # 2, used for the laboratory shear test Lad preciacked while in service and therefore before testing. The thumbnail or precrack arca was badly corroded and revealed no information about the fracture mode as seen in Figure 4 at 500X mag. Macr 0 examination of the remainias area of the bolt threads, Figure 9 at 10X mar., indicates extreme metal loss in the form of pits over the entire surface of the bo!t. It can also be seen that secondary cracks have developed in the first three thread roots adjacent to the primary fracture surface. The first thread root is shown at 35X ma g. in Figure 10 e d the second thread root is shown at 50X mag. in Figure 11. Simultaneous cracking has developed in :he thread roots in association with the corroded crevices and pits in the bolt surface. Figure 12 at 35X mag. shows the effect corr.slon fatigue has had on the initiating fracture surface. The #2 bolt was sectioned and examined using an Optical Metallograph. Figure 13 is the second thread root from the fracture surface. Corrosion-fatigue has initiated a crack and has been enlarged, and accelerated by galvanic corrosion, followed by small cracks forming at the base of the corrosion pit. This condition was more evident as shown in a photomicrograph at 150X of a cross-section of bolt #4, Figure 14. In this instance however, additional corrosion has occurred in the newly formed crack. This photomicrograph was furnished by LPAL from their primary investigation of the failed bolts. Bolt #3 broke during the attempt to remove it from the skirt. A thumbnail precrack shown in Figure 5 was scanned with the SEM and showed that this precrack area was protected from the environment and had failed in a tensile mode as indicated in Figure 15 at 1000X ma g. There is no indication of progressive cracking, only microvoid coalescence indicating tensile loading which could possibly have resulted from overtorquing during assembly. The remaining fracture area was smeared metal as shown in Figure 16 at 500X mag. The photomicrograph in Figure 17 is the cross section of bolt #2R which shows a shear fracture surface containing a heavy oxide layer. .The disturbed metal has flow characteristics in the same direction as that of the shear force. This bolt has a different microstructure since this bolt was made from AISI 1040 carbon steel material. One complete bolt that was removed from the segment seat skirt was sectioned and macroetched. Figure 18 shows that the bolt has a forged head and contained no major material defects. It was also noticed that the threads have been rolled formed.
' l R. IM8 ggy 33 39,g E.O. 25504@2 PAGE5 All of the remainlag bolts that could be removed were wet magaafluxed.
Three bolts reportedly ladicated posalble cracks la the thread root adjacent to the head of the bolts. These bolts had been heated to very I high temperatures la the attempt to remove them from the guide ralla. Therefore, any leformation derived from their examination would have beca questionable. l l PREPARED BY: M / Y-g i RAY VD EL, PROJECT MIITALLURGIST APPROVED - AM W. JDH SON, CHIEF METALLURGIST O O
O i i APPENDIX A COMPONENTS AS RECEIVED CONDITION O O
-,, .:. cy . r . . m .y ,y ~ ,:r c' 7 w wwfer --
1 ..V te s.. > .
'. ? M. w e. ,.:n,,'. ' .
d.;c.< .'M.aM: .g\ .W .? h*Je* ' hwig;r....?p.w,,, u .. u+ .. < n. W{+$. M., . 2 ). .c
,',, ,t=79 P{1;W ?'3, r@.;. :-fb...a,,;n.
.; g p ',@ 0} W,agy , j-l" l >
L' J W, R , , :. , .1. .,., m ch. q ,; h ',g f . c. ; , e og s ' ,, . v...e.rn o,a m. tgp,t
<t ,. *p e,to
- d..5, A Qn...l b, -twre f .
N,A{q,r}12,, p u it H 6 .g:
. 41.a,g[l M' t s
.x. M L. . .. W, rJve .n,n N .,3 i /*bE h ;gn, h: l U /$ 4' s -. - '
Of
%? pmW5 4c 410 a [;>f[@t bb p gi., di..mW"P,M aQ ];.pqi p JM r ,h.
W &$ e b.$g? .o ubN .-O f* W f y h W # a3g W f.m p.3,t p y' 'I Q, y;! I eq1)$,d,- p g pg y @l;C%,rkg <. q; 3
,M,w&,Y,+.W W.W%;%
4 n 3,c wt g.y 2
.g, s
,ng.
. ,. ww M.)$j./ M'14C e.suu W
A p,..R% pt/W%TAv p a t.lw
*g. t .a; J
. %,, o- - % d.4-w>. M ,n q3 <
s 3 ; i Il. h, 4 9.m' q3eI .*w. ; . u .. E Y ' ca Y..'n. . .q 3 w. . ,. J
.,i y%} Pw th .
..d. 1- op' pyTI1 q g d.4 n.. n!.wh,42ii Up
.1 ., . ,q pr,g4 , ,s v r'. -f if4;mtn s .
? N!d ...r.
o.3 PJ Mf ,h,.-x+. 1 t-gr,. d. I ;:1 ': ,
,rl M.I. mg' . i 01...
' d* /i r m ' .Me.
.}
V, d.; qub,,}i,p k p &, d o,.i-,.
~+-&p",i{i H i O.i *%g) W l i,p _
tN i . > t m, t ;e<i;qg 3p. y
.i #1O7?Nh
~
T.yWf;r
.O. a. p.?M f'Q@
4:::mr. a t. Mow.tv:
~
i- I
't ,.
~ t@ q;[CIut c ~ M hy;;%f.-[%p' 1: ^ )..fr 2 e
p :. t
,-3, i , . y
{. f D V@:%Mt!@h!$MSMM i
!!EITALURGICAL REICRT 100598 - AFIT]IDIX A E.O. 25501-002 E.R. 7840
l l l l
' ~
3I' ; : . . * '
- y. :
.g.
4.
~
o
. u u
..64, . /.
n . .&. - ' {. . .;
, 4 -
'l~
. , . ; .:t , ,4 .'- ;t ,
1 : A. .t t), . spy
~
, .P l ~ t t.
. gg
'A i ".
. j l>J .
. . . m.
J
,1
.. s;.1
., 5 , .
i
' N l }
i b s 1,) . . . sp . . . . . . . . Nr . 'di e b i h: , r .
.' , . . ' )
em .
, t +
l
- . i A -
9 s.
.3 . ,
. . I
\* *
.. . ._ f* w....
~. , . g ., . , p -
'4 nrX.;
W, ; .
...- ..- v;
...sy ., . . . .,
' ~ ,
't" , . , 'Q .) . .; a
. . v p * -
.g4?.,*, 4 .
A .
.e. .
n ,
- c--
">g,
,.w 3 . .
, ,a *r ;
-t t;< , ,
.. . r. 4
< ,o t , ,
e /, ; . <, : r Y u, ;
. . . .: , a . . . .
L p .,p p s ;m s. w.' < r : 7 ng e.%,.2: , . . . .u : - ..>>c.b .- u, . y> s.-y y, .. .9. p :4
;- vu <; >rn hiYb n;.g.w?;h? 5h egr.n ww n Y ' t-kh 'i.'.0; Y. bIYI q:'fk u c {$h.hq
?'p19pn.TL%p,$'hbf?
y hs .t y .sta n W . r W P M ) v:. : w
$9m -; ,. ;., +S
. ,c 5 s n y v:..c re :e v'1 a.;a:.
.34&O Q %; :,@.; /.- . qs., b ";
','g,;Mi.
mpp%.:$(4
!!d(MiiM
%D:fyfit
, i,;wua 16,m ye. .
r
. y .;Q e iWV .
ghe;[%nx.y.,
/ d f r% v. n ,i.ys,4.y Q .
Af[ %pus Q%%p 7@ t n y/a iMN- ,a!p(p n.; An,Z. d ffj/; Q sj.;[pm 11F'ITAILPGICAL REFORf 100598 - APIT11 DIX A E.O. 25504-002 E.R. 78:0
I I 1 t . t l .
/
b e
., pn, -
.c ., ,.
-).
- + .
, , 44 % r: .
u ,
<. - < g
. . '..(. . , ' ...-
, 9 . .t4 .
q ., p
-{. ,n.. 3 .. . , .
. ;- o. .
~. .
...J8 4 '
s7. .. . , -
.4 .,
. ,.. . A : c T ~I'f~' E sk . M*_T -
- mr_-_...._______________
),4: '; s 'j -. a-n; t-r#[ Yuk .!
*.
- h %' %\i y; ' -
.,,x@. :.ap . - y' :-, r@w . o
- ei 'I-: %- } fd,Y)h a a- s -
- ~
,#+g 9 .,
,- /
}
).
.RW .. .. ' .= e 4
- 3 -
\.
. t k. . 4,g ' # '
g *. , , ' %[8'.
- 1 $ . ~
- ' [- p :, -
In . . -
.je K %*n *k .o :, ' -
eep'gh i -
,M'Ntfg.%?nMd,
~{mrJ9MVMN dfMgj ,- :,-
fd . b - t -
~
t- 2 J.E. a fg;in;ls
.c ll;n:n:4a!s%e!.!,+il.:"&,O.i.~R.M,. YE r t: W'4 n +~^* D M 1 9,? ?.ih~i,m%,a.<t,r-y%g/.
'T ' * ,-
~
. s',,
.:..g N y.p, , m.-s w - w c e---n. a - - - - .- -
.'4
. . n , W ,;g 3 ,w,a ;;,. 6,s ;,;,. , b:0 QE : 1't>iN6(J$9#f M N;g ITI'rA11HJICAL RElvRT 100588 - AFFDIDIX A E.O. 25504-002 E.R. 7840 !
1
s.
' ' ~
l l
/
.4 4f
,'. ' g . * <' , '
r' ,
, , i . . * .
. ,s ~--_..i. ..
'.a' ,i y '
Qf.y:'p T y, . - .. r; '_ -
- . - . * . .. or ,
M O
' ! ML
, p; :;tyg Q
\. '
l
' . . .* . w. $ 3' M J =46 6. f y f.
y s. w ' 1 O lie'ITAIURGICAL RENRT 100588 - AITDIDIX A E.O. 25504-002 E.R. 7840
l I l t It
....n I5@ .
V d?5 N. F p : a ep, , _
,. n ,. n .
~ ", ?&
4
;F. ,
>t
.L:..
ikhi s
~ d W i-.@,. .,
~y e Nrn '
my:
;pb"As 3 MQ 4
. . e. .- s
_a j7 k.O.g . v-i.- * ,
. r. .
.i s '
P i( . hp,; s -
- n. ; ' , , .
M+ ?.i
,3 : g.. T ? . .
m .3 i - p.r%8: :,4,9y:3 *'r 3, ; - (li1:2 4' 'M ,.3 '- ? -
-(
A -e, ,.
.i _
som. , - .3 'i,.; s . .. .- a s . . . i, 3 ., -s +. , :ap - . .J t..*. , ',
.'i 3 g J* Q i% ,,.:
~.%'A.,,J,.)llff't.'-41'. :.< _ ;f.kd ' o'.i.n, . , .
,e j
- . -?- .
w
, 7.; q . . . . , . .
.- g -
u ,. . . .
- - - y < yggt r- ,
1
!!ETIALURGICAL REPORI' 100588 - MTDIDIX A E.O. 25504-002 E.R. 7840 l
l l l
. . _ . . , _ - . _ _ _ - . . . . , , . . . . . _ - _ _ _ . _ _ _ _ _ . , . _ . _ . . . _ _ _ _ . _ _ . _ _ _ _ _ . , . _ _ . . _ _ _ _ _ , _ _ _ . . _ . _ _ _ _ ___._._._,._._._,,_.s
.g,
. , , + l
, , , l y{p ".
l i l 1 hk,I l
!?:n o
ty%g rw.I blefiM v rw t .a '
* ."j,A ' i;
?,n p;' ~
'l, ~ge: lr% e e?;'&.Y r,,J
', ' pg',;f.;:f'::b;.n..n s:~ , ..
t
,g :)
,,6.-
J1 l
- ' '% l 3 ;" ,
l k u , . f 1
#. e-4. <J..>' % . ..
.~.. :, u s _ . , ~~,
, ,#.%pkThi/,N Gh
- pdt; 7 c. p ' , +.v M. -
4 **8 4 d el 11L'ITAUJRGICAL PITORI' 100588 - APIT2TDIX A E.O. 25504-002 E.R. 7840
l l l l l f6A-Yi! ..,
!': O.s:"- ) .r; ti.;iiPT s- .., ' i.,
. y;<
', p;y;:
>< , p* 1 4 '
'~
taA r,- "l_(
~t' ('
.s, s
,., 1j ;'vf..
- y,s o f, ,, ,
~;m- rug ,7
. lj * "e \
- ' i-
'O S & * .* '
- e' *,.
- g i" y;.s i .
* , .. yt}g . . . g n.+_ . . .. 'yp . . .. . . ?' . .} ; ' , _ y,, i
- 1. .y..\ '. .. . N. s.' ' '. .; . ' ,
g . + 2 : ,. 'b 4 w ... - N. t ' gW - .* ' f '.4 I E ',_',A b; -f - _- '. .g y. . ,4 ,y . .e . ,. <-s e_ ,,- - . / -}_...'. Q' * ' _, s-g gg ,- w'
- w, . J o* -
's ..Q. . A. '. s -. .n , , e V . .. . MEIALUEICAL R5ua 100588 - APPDJDIX B E.O. 25504-002 E.R. 7840 NE2 04 #5 #6 ) #3 ** O " l ,1 O O O ** O O o *o O o CHAMFER END Q ,' I . 1 ' l e .. . . _s s .- . .g . k ~~.-. .. ~P ? k. " 4 ,N < i, c .. . . .- #3 f'- s 'n - y , .: -w ~ ' O ~ s s. . .. . : L ' . . . . l u ,( , e - o .. ~ ~ -f.' V . l - d , .= , y . - ' #4 ^ s . W' . ~ ww . O . . MEIV.I.IHUICAL w nid 100588 - APPDTDIX B E.O. 25504-002 E.R. 7840 04 05 #6 g ,1 O O O O ** O O o #9 O o CHAMFER END Q *V ' . f* + p_' ' .. . .y Ui. . . ,. .f"1, ' .P. A - . . . ' . . .P.N . . .; , .,,.3,., #5 l ;y,..- ':' \. ... w ,. -,,. .s , - .- l _ e- . ~ '~ - (O - - .. ,,e , .. 7 x ..A i I s .._ " .:. ; ~ . \. - l . . - se . _, , l ys, ' - , . - . i - , p ~ gg . . a.... < , ~ <: 1 Q .. J'f . . , MEIALUEIGL wmcd 100588 - APPDTDIX B E.O. 25504-002 E.R. 7840 4_-- _ _ _ _ , .-- - - - , _ - . _ - - - . - - - . . . . . _ , _ , . . - - - _. , , . ,._,.-...-.____.--.___._,_...--,,,,.,w.e-,,,----...--.=_' l M4 .4 os ,g ,3 #2 ' '- O O O O #S 'O O #9 I O O l CHAMFER END r i ., ., j
- . t .\
/ % s . , w , . l >u. .' j. ; . '- 4, a 1
- g. .- - . -
l . w-g_. - y , n ~;qq:ggz7 g.: ._ '... t (gpikhw 1 . .i T ..v;s . r -,....' .; '. . ' y . - ;' - .
- S & . ..':'? . ..
- - , . _] ;. " h~ . .
#7 . I s t .- . - r q ' <' e . -M. . q 9 <. .f,. : .M, h .,s > .c - ., . ,gp, 7 -- , ,3 s .c : .. :. . . j-L
- f. _
,e .,{ . v ..:- . ,..y .- .g,' . .....,3 . ^_ ,= .. .. y, - - , - #8 ... 3 - l- . , f- : . , ~ .;..g O -: - . FEIALUJPGICAL m2 aid 100588 - APPDIDIX B E.O. 25504-002 E.R. 7840 -._.,,,.-.,..,....,.,,,,,,._,,,n, _ _ _ . _ . , _ , _ , , , , . , , , , _ , . . . . _ . , #5 me5 #4 #6 #3 O " O O O ** o O O o #9 O A CHAMFER U END s e - 4 - , ,l . - #l.' ^ ' ~ - ,--. . c. ; . ,a = . .3 " ~ .jg,-[..,, > ~'-i...,;.._, .o ..; a O MEIAIJT.URGICAL REPDRr 100588 - AFFDIDIX B E.O. 25504-002 E.R. 7840 m , , n' A A O e APPENDIX B RIGHT RAIL ~, O h a .o PAGE 1 i #6 #5 ,4 #7 #8 #3 O O c# O ,2 l O O ,1 l O o BOLTS #4, #8 8 #9 CHAMFER WERE REMOVED BY LOU _I5IANA POWER 6 LIGHT END 6 .. / . i . .. / . - h
- f. -- sy ~"h. .; r ;Y - ' '. ',?c.q.._. ,
~ . ', . ;:r - j. g , p p..- . . . ,, j . ,y , ; gi ..- i M 'c .o .. . G ., I . . ' , af:-[_mug. , .. M :;= . : . :. - :. . . =r- . g ~ ' . . x . ,A ~ [-~ - a s ' ^ (; . #2 ) ' '.. ^ O ' -' - MEIAI.IIEICAL m.wid 100588 - APPDTDIX B E.O. 25504-002 E.R. 7840 PACE 2 #O $ #4 #7 - #8 #3 #9 O -Q Q #2 O Q o *t O BOLTS #4, #8 6 #9 O WERE REMOVED BY LOUISIANA POWER & LIGHT CHAMPER - END . s- . o / - . 1 .,x- m . '~A y .:n fy ' ,Q * , . . ( ._ ( _ _ f g, , P' '+. _ s .. :- ,[ s a .. . -jagt gT;. 4 , 3_ _ . . . g.. .. r. ., ; . g. , . . . .,.. . ." ~ p';} , - . j ': , ' d' g3 l . .. g. c ., ,,, , j - . g, . :;. , g , r. : l 9 . _L, ;j . 1 '[*' ':' - E . . . 5a ., / L .. , ~ . l l ='( - . s; _ _ . . . .3 . % > .~
- s. .- .
' '. p I .,s ..' < er,' , - - . .
- l j.I .h &
, . . . n .: . . . ;;p... ' - a 4 _ ;. 3-- '. s ., -V ' . . ~. . ~ y _ ^ :- _ , . ,- .. 45 . . ~ r *: ~ ~ : . .. e . w;l k 1 .. M , '. .I . ' .j . A .- .e , '_s.- - ~ 1 l l i i MEIALUEICAL m.wid 100588 - APPENDIX B E.O. 25504-002 E.R. 7840 { \ -- ._ __ _. PAGE 3 06 5 g4 #7 * #3 O po O O O #2 1 o O ,1 l BOLTS #4, #8 a #9 O WERE REMOVED BY LOUISIANA POWER & L1GHT CHAMFER END ,. i ' V. . . ' -. ' . ,.c- .. . . .h:' . , . ...,;:,;9.- _ - [,, ', . . - , ,. '1 .'a 4.f ,f'(, 'dh[N':h'3 [ ^ ; > . Q%" ,i % :.* ' y f % $> W :2? <J. :: ,. , -, . . g.< [gp ^ .g.y *~- p
- . .f..
s d -- : *. we; - . . ' W- ***. ' r.1 - * .X: . LQ ,..:, (< . _ .i :;~, f } ; , ' . _ _ _ _ . . , . .. / +-. .. %.w; . g;, , . . , .- - *w n- ., + .g . . b .. '}. . 'j . . - ~ .y . , ._-. '. .,y vi ,, g ;; _ p ;__ip ,;; . _q . ;c . .c . l l l l l 1 l O , l MLMCAL i<ER.ac 100588 - APPDIDIX B E.O. 25504-002 E.R. 7840 v , i l- > P l 1 l' l l I i I i - l 9 I l t I APPENDIX C r k 4 CHEMISTRY ANALYSIS l f i AND METALLURGICAL EX AMINATION PHOTOGR APHS j i i .s + 4 l , i 1 t , a j u 1 i 4 i 7 t l i . + i 4 1 4 i - i ~ TABLE-1 , CHEMICAL ANALYSIS (PERCENT) , 1 BOLT DESCRIPTION #2 #3 ELEMENT #2]L. # }.]L. _.#.8.2L !*8L SHEAR TEST TOROUED CARBON 0.379 0.357 0.346 0.376 0.347 0.352 PHOSPHOROUS 0.028 0.016 0.016 0.015 0.016 0.016 SULPHUR 0.010 0.009 0.009 0.008 0.009 0.008 MANGANESE 0.79 0.72 0.72 0.73 0.72 0.73 SILICON 0.25
- 0.23 0.22 0.22 0.22 0.22 NICKEL 0.06 0.04 0.04 0.03 0.04 0.04 CHROMIUM 0.14 1.03 1.02 1.01 1.01 1.01 MOLYDINUM 0.252 0.250 0.248 0.246 0.248 0.242 HARDNESS "RC" 37.0 37.5 38.5 37.0 37.5 40.5 CORE CENTERLINE l
l I e i I I I l l l _ _ - . _ _ _ . , . _ . . . . . _ . _ . . . _ . , _ . ~ . , _ _ PAGE 1 0 1 j A bc f 3s). ! .. FIGURE 1
- .s ;
w we o ^; \ ' l _ is I, , FIGURE 2 . :- <:; c (. a ., r . ; ;- - . q.n ~ , , ?h ' . ' Yo - ,) -,wty ~..;3.- . y: jy . O ..u MEIATIURGICAL Rt.iuu 100588 - APPDIDIX C E.O. 25504-002 E.R. 7840 PACE 2 ( c . w ,.,,.,,c. e. m -- , p; . . . - m mu. n. .v .;~ . x .p.a,. - ,9 ew w. (%, a. lv - .,,; , s s " a< < A g hpeu;g;,y ~ .c :,+ . ; <:;; . E,Wy.+vo(. 4+,maa - . . .. <.a x .: : - W, ',AM - +. m D; R, ;@. . .. u - ---4 uc - %a.~ .e. W:. c,: < nw,::x.y u-3m. >.m +94 a .4gr ' ,. : %a . )q F, . ,,, .+%,s b-v ~-tc+,, ~.%yfgeb: . V wr _
- A 7=qs 7 .. 1 .
ys , ,:% q 6 - Ao #d**s ".A.*N'" s% . ', ., s? a,w.,'n-:' a ,i, m,R sw. *'s4 ' u *. ,-. .mysc. .D, g- , *" ;CJ~,.J-' *hg'g.2 . a,i;; :}::% A,;x'Y W ?*a L .K.'l, gy,' '! %o.'. e s .J'. s .. . wke<,:44-~N. y s0 o -s w a k, M. ::,;r m.4:p - 4
- n w w.we .7;h aa:n .~
wn . ~. .L a.e :f:Sc;p., ,mm.s-s mWp, ar*' m - *> - ? ,s . gn , . , 3. . ;
- -.p . , s ,
-: , r *- . v %w;p ,.
- a. m,. gy'
. ...g.- pq.;4 - f. pA' .4:, . F FIWRE 3 - 4tw ty . c w- \' g / 'N. y=[ i t ^'V @% ' - . ...f+ ;:9 hj g;. -- . .Jr,'i l, Y.h4 .
- s. e' i
l i wwim. FIGURE 4 .i <i) ~ ,- I !! 4 3 O n. MEIALUJRGICAL REPORT 100588 - APPDOIX C E.O. 25504-002 E.R. 7840 I PACE 3 co - l g, ,; .. ,Y i '_ 1 p pp.; ,1 _ e .< gb c.y. 4, I <- \ Np : .p,y.'l: . x . ,. . .w . ? ' %~ _.. ..f j e l i ~*
- j e
d . MEIALUJFGICAL REECRT 100588 - APPDTDIX C _ __ i 1 "'" ?":l* _ D PAGE 4 ~ ~ l _. ' l- ,: - .: .- .. ; ~--h; <.~ ,,. .- . f 'lx .l ~ ~ 1 ' . .. .f't R,J' Q }: . :, > l ' 's, .) ', - .. ' .'l _ 7 . . :M ..,,,1-*.,,; ? 1- c '. ,,.. .. .. ,- ,y+ . -; i p >$ <[-. .. .y ; p.. * ~j r . g -y, . ; : y1aung y ,p*g. ~ % -- y ' s , ' I . 4 %-) . ' ' ' ._. . ,or-s. [- As .
- f. l
. ~t w:. v . t j*L }, r sc
- 2 ' y
-Q.= w .: 'c. *Q, a ? -Q %eg , *,-.+.x6n.n .t l (3.;.!.! -. ,~ ', .- .~., - ,q~$ .:q. ~yk' %. A, m... .~ . n, , r n. - 5 v.,J ( ., ' , ' N, 1% . g Thi mpW ,X. p- ,.g y* .(*'. 'i , r.3 + ?;,. 3 .r. -42 , l l l . , 3 , , ~ , i % ' . > 'J., . ! ,. w%
- l
.e A ,.,", .. . . l$$.
- pie ..s O ~fa '
,,e Y ** ~ ~ ~ -; . , ~. ' ' &ar.y .- c - 1: r 4 'g ', FIGURE 8 f 3 i ,=e s s .s. w . f~1i,7,3 a ,. , . .. l e i O 1 MEIAUI.mGICAL REFORT 100588 - APPDIDIX C E.O. 25504-002 E.R. 7840 a s a - PAGE 5 t {}f{>. . j.jdXyg. b,. %. ' '1 ; , ; ,y . n .l .4 : , l gV .cl ' ,fg f, ' .i . ; s.hf..f.: $ h% 5 ' {$ ?ll: , ij'.~ ' : . !t' : J. ' ;f . , i j- ~ ; "" ' ..j .% ) 3 g .'.. i j .'s ^ . . - Q. .:f.N,hrg? {.j j'
- n;.=, 5 , {2
$M J ." ? . h ."/" .'; , /p ' ,, t ; N 0 ', 'f4=;n +pg% w f" .$.t 1 . g: " h_ . . n . . ._ a2 ~ m.' .) ;, . y . A E , ,'i - 3-j l j [ j. l 1 f: , h .f# f l""
- q. ;2 1 ;
f 7 Ib),9ifA') J . l) ' 'd . b' 2 i f l MEIAUlFGICAL REICRP 100588 - APPENDIX C E.O. 25504-002 E.R. 7840 j _. i 1 l 1 l ' PAGE 6 l i ) . _ . _' i l 0 , s .>. ~- <- 4.s - . r , +t ur . p)' G , ).s n V . P' ' : , Y \t t l t- ts] 4i f N, i ' 'g \ ( y . )\ y - . .* ., 'a (* p,. y.<.#.. ' y n i- r'b,-l _. _ \ 1 .. ;-[ 1. ' g, i I i . < - : s.: i, . g'. ~ . 1. .1 t. '.:. h,, , C.) ~l . i '\
- r
(* . k., .n l .,3- . y ' ., ' < t- k.."f - y [ s ; ..' t' ' , filo,s . ' -. , .. -,'y. ' FIGURE 11 s'4 , f , ,: "[- k/.: f.,,-. ; g ,. O[ h. 3'\Ay . } y,: f. ; '. %' . !
- .-: ' ' . _., (Ti 'dq.- ^., ,
~ ,' k,' ;' ,-
- u..'
l )., S k ::n:?.n cw- - ,: - d ( j.yk{:k Y's'- .
- r. ' ; _
! . j ' , ' :: j' ~ ' . 60 = = = ~ i ._f & ~ '7 _Q_A =*7 _ "i - _ M , M V'WG au:.,. N .s',.g ,. . N . '.%.'* v, ,.w%;w.r%,. w .,5 % . *40 W.CQ,W-(~$$K \ y; . %.. . i * * , . .f. r: 5.e r: - Qsg. e - . .1. m . . A.w . . p.y,.r..?. ,,y. .. . Q.~& .. '.. . rg%.FIGUPE 12 e.;'.,,'.a.,, ' 5' ' 9, :..R. ,f T,*.'. y.,T.vQn, . .~ .wia: . ,; ~. * ~ ;. . .. ; 3 , ... . . i ~- .t /.g..:,,;.,4 55~Q 4 - ' 1, ,~.- :,. . .; p' m , g h'-;?'S **.=. T .~ & ~ M :; ., ". 3 .. :~.' . . -. :' -;~ ' . ,,*'W., ? .,;- g: a.,_.e: 'h m ', q. ' ^ e . ,w $ ~ ^ # '.? . q , , ,' c, ,.. d. 5,.A'.v~.. [: g g _. O STALT.URGICAL REPORT 100588 - APPENDIX C E.O. 25504-002 E.R. 7840 PAGE 7 s GSA'** s gr> .- .l [o Y / . -* R <* - . FIGURE 13 ^ p, "[* . N * ;' p, p e = s Q. . , - . ,s lj.D g, , , . ' . t .. y;Q . ' - .,_ *e.Y , ff l *,4; ?\'$ 5!?1 n fPE ?" 'il?Wi4?',*q,-," e . L ..m ~ ^ . ,,) . i:$ Pi% hiB}h7 k e% - A&hi;it m ~ ~ ( .- m@y.: ,,4 , g"$kh 'f, Pig, FIGURE 14
- 99. ~. ~
LM . .s : . ,," , a i &N Y' Y$ -e,dM#[e?N-?[$.i$l ,;- q ? %.q'4 . "M 4L -. O l MEIAIIDRGICAL RUu<T 100588 - APPDEX C E.O. 25504-002 E.R. 7840 PACE 8 D 10 k;j7.,~'R$]@I.'.j*[N'h.;%%' ' g s ' '<* ?.g,',,g i 3 J'K3 * - ' ,/
- )
l Ij ' #..Ws , , v. s,s -: v, p- ,s '*l bt' ,+ ''t,,.. T g ., / ! .,. . ,] 'i . . D :,,g ' l 'Rg,. p ,4 . 4 fi - !k r k g . FIGURE 15 h s , ', .. k . Y . s- , M hl % ~ sA . x 1 h h. . (O ~ b : h ,. J. - -s 4,. * *0.'- ~ ,.4%v. s, ' Q .'=(- }* ; ,\.Y. s.. y- * .- .xv ' *y _. _ R,.r.g; - - T- '- f .. $ "' , t W,$-4 ...t-n ' P .,,'M.*5.?;. ,? %&T >- ,. . .,.- J '. ', FIGURE 16 , I' JE ',. .. '* ,- [A . - g%zQ.qL. Er;j-~'e% . '.'i,1 ' . f~ ,4-4 . I e+ t . R..i.$,: .-;,t ,.... .m. .'. . ... r,T:.,.. . ?. . %) - 2- );) + 'm .;, - '< a . *. , ;. a . *. e,- g. ~ - .- -r c :* ^ v.' ,.. e. - py, . - . . -- .s . - $,W 5 W,~ . v -y: $... yl. &. - f ' av. . ...lw. i ! i O ! 1 l i MEIAI.IURGICAL i<.t.wi<r 100588 - APPDOIX C E.O. 25504-002 E.R. 7840 PAGE 9 i )t - )F , .. & >r +. . ,v ?g v h* . . .s , ,' ,h M^- . , ~ g4 . .. , j' 7 e. A , ; *
- FIGURE 17 3 .
. 4' , .['s- % _ .g,
- suc. z w. -. '
;- . :s .. - .,f, . '. .f. . , [ . oj hf . y, ' .. ? %:# ,i f l'.h.. lf'? N .fprJgf *h.w. * /,. , 1.," ,_./>k ? . . . , 5; . i -, , y' . 3. .a ,. . r % r . w . > . ? w,.s,. q ss, . - ,5=?YNN?5 NY?5l'?) UhN d$rzk,_ a ' ~ ~ (D 45h Y , zi! .,y$.bU ' Y: e ;- 'NiN ' s. FIGURE 18 e + ,m..4 - sO MEIAI21EICAL Kt.wi<r 100588 - APPDIDIX C E.O. 25504-002 E.R. 7840 O E.R. 7834 E.O. 25504 001 APPENDIX G VALVE COMPONENT PICTURES O O N OF CCNPCNDUS MIV NDCEL D2 PRS MSIV SERIAL NO. 506157 WID MS.MVAAA124-A N NO. 22 -V602A O APPENDIX G 1 l
- I 1
O 4 4 E.O. 25504-001 E.R. 7834 4 4 ..,,_,,.-,,_.m__,_,,n v.m_na,-,m,n,,m.. .wr _ wm n_ w l SERIAL 110. 506157 l UliID FS.lWAAAl24-A l TAG !), 2MS-V602A O s J. Y- ..)' i gg hI r an b'dS' O'ML . n l Y hk b 11 i f. e $$hy: % & ',". i l 'M Q di \ i
- \
'\',. 9'14 , l 4 - uO W .c y I; ; s" c, lh ..!
- 3. haseil-l y
..l'.j:l .? 7 ;;c p ;:u . -{ 49 w ;,) s s .. . . , .- . *' s ~
- fS 9 (i) 9 ;.y .
~*, ' [ ,,. *'"..h'g, 7 .. 6 ,. Ik, ;. y' . A. ,4: , ., . .t ,. . .,. p $.S.. y. g. , } i . ..... c. l , p Q. y . py.jd.'. . # V.
- 4( . 1 'As * .
' k f[. . $ ' ',8, { h,,, l , g'g . 9/ h '. g Ii'a'f j g p Jg l h ': .y ' I I I.'s 'p t lp Q $ H M: M*g*(, 0 15124B SD2Off SKIRT f$. i d 3rf v[ , y) , q.;g . ? . i i,u y .- N W W W p f g Q :.p ~ . [ -P d ga
- C-%.QfglJ f3 g 4@g.- ; .3
'". &1 b t ~S , *kf, II i jf; e a:, . Q. I [* 5 #...s.s: 3* [
- 4,',
l,.,.
- h. M 4.. bL
[. 'M * * *' E*g , ..x *- N "Q4.'N1%!' $' '.U"'"-* . ,. . ' . : . . . :.. .q .. g .e - t' u .g f.f .-'j ..t . .as.s. A j .4,4 4.,*'....$ ..y'f . ,, 9 g .. . .. , A-r. , ' 4~ <s/f, .q ;- . .. ,,f g ;,,. ' ge : ' . . . 47. .4e .9 - 3 k e ..a.,, .e , l , . .-:' S, g * - a .. ' 3.l5.g-+ifc;
- g. --t ..,i e ,f .
, , .y.. . (.y . , y .-;, ,.;-. , -. z.y .a..;_ '; l3 , : l.- -ltj3 N.? .~
- c. u ,e
' ;i , .. .. } \ if:QlS.,(_W.e[,rl: L (.i ':. f :_m?l_ , :.z 'l A fy[f ' b ;.,' su.M;.._q,,, ..< .' . . - iv. . _;'Ly'r;, . .4 ,; . .. &. r . ; .. , , ..,9.g7 . . . .a- . ..,,.... g. . .. . , c .n , .l ( {: f :.1. ! <y -l l Ql .., 1 j .;....;..,. .h.~.?kf)fl.?[q h ? l $'.]i.'.k.h$%. f f j, y;;y .m.s:9;n;p;xmy - kN. i ? l k - - . o : O E.O. 25504-001 E.R. 7834 AFFDTDIX G l SERIAL 10. 506157 UlTID MS.MW%%124-A l TAG 10. 2MS-V602A . O y p w% , w c._. , m.j., 7. .y.n, .' j I ~'8', .;, [ $;l'i"[b:.,,%^ g, 2 g ' : . ;_. _ , 'vgI.<, _ p% i df
- j . .,i a3:T.i . .:p ; :y,,,
. .,,...y Q ~ .. y- - ggJ. (;: ,MM, V. .'.. . ..+' - i ..,g_q? - p fikh h A s e(3Y; n%I...$ , Qn.p . s !W v.tg..4w , O MS 124B SD2!E2fr SKIRT I l O E.O. 25504-001 E.R. 7834 l APF12iDIX G 1 l SERIAL 10. 506157 I l UNID MS.!Mtb\124-A TAG 10. 211S-V602A , 1 1 , ,. - ,. g , , g , 1 t i g .. ? V~ t E , , __ ' MS124B GATE SKIRI-SHCWIl1G GALLIl1G PAIL i gif . rt j,.. , -- , 1 i J i , ,, 4 . . 6 s, ,,'+a .l, j { - .g,. L . **;- , f f ,.7* a5 g, ?_ y- s - p, , uj . \ ~, a; . . , > _ rui, 3 , 3.' , ' . +- 7 ' .. . ,g . . 's . ; ' . i ~ T. ^ NY??(5bNb!O ~ , . . n? tJ: * ~:::::::~:,,
- f. ;.. )' - .
tr.M t:mgrLl /.r:t a r n ,j: : :: ~ : E *.* "i , 1 ' Cl::: tt Z ti;' Z 2 ? 07 : YP. t .) ': i pt::L'rirr;::> :.t f ud -.n l ~ e a ' ,t,' ' ,' E; 7. .'.* ,' ? ,:,. ..':j < rJg'. .- ' :'% .. . :: . r-4 7. :vb~4.:..~...' : ; ' '. r La p ;; ,.,. . .. ;- .;.s 1.: ;;t ; .g . 4 . .. - @' q:;,D.:u-:t :, d ' tv ^ .. ; "y ,4 , 1 r- . , # t'{ * ::;t. t 4 0 ;; e i <a r.*r9t*g~ )j- '{0
- g+. p y'v}hig; 1 -,
]. + -1 ;,9y,T[**~"<+'[*f!g.g 2 g; .. e-r.( 9 ,, p"p; , ,;* r : ,;f,' . + f?. . ~.l . o y ;g*t . ,; ,,,,7 .~~~.. + s.,~. ,,, n -; ! > v ?,:' { $ f *$ 'f,h N 0 b $ i l^ ~, ) *; ') " (,' f;f t f, y, 'J rT yl f, A, ' P~P: Fdi.7e' - ~ ~ ] _' .. ! -{ d&W$&OdL..h.*a ' *i .. e 'E N M :': ' MS 124B SHOE 'IOP AREA GALLIl1G 4 E.O. 25504-001 E.R. 7834 AFFENDIX G 1 i l l l l 1 1 0 l l i l l l l HDICGRMHS OF RESINING BOLT TEST AND FAIIED BOLTS FRCH i S MIAL No. 506158 tlNID MS.MVAAA124-B TAG NO. 2Mi-V602B O u - dix o i 4 I 1 9 e a i i i . 1 O i ,1 E.O. 25504-001 E.R. 7834 i SERIAL 10. 506158 UlTID !G.MVAAA124-B TAG 2fE-V602B O ~ w-,.. ,j , .f . ,y q - 7, 2- r .Y?!r?*j-~ 'CT.: l" C:,i;- :. :c:'., f ..p_. ~ j .2 7 ((W,'u;. - - - . . . , . . ,
- a:7[; . "
. . -*4 c ..s / s rd ('W , {W f . . . @$' \ilk %QQ > , MS 124B SEPARATED NTD FAILED FAIL ITGt GATE SKIRT pm~ w. . v . ! t s. . of .jjg ; ,w . ,;,p . 4 i y V . . , , $ l I l .. i 1 l i t ) i . l ' u, l t, e an ... . ;, c .. e r- 24Y91M + _ ,3 y; , s..' -. ' 3- v: " :j O !!S 124B D 7Di GATE SKIRT PAILS-ILLUSTPAT11G RETADIUG D3LT FAIIURE NTD GDF~. 1 i E.O. .. M AFIT2iDIX m 1 l l SERIAL 110. 506258 ) UllID !!S.!T&TAl24-D j TAG 2fiS-V6028 l , e . ., }l '6 .@ . . l ~ iii ^s .) . l e - t ,_, , . _ .. - . - 1 .s+ \.4 - ei . N' f; [' \\ ' - .sz , , , g4- a ,9_7 + l ~ ' s - * . i. , , . ' . ja g .%s., ' .g4 k { v:n + ,
- l. . ,
. S. ~ - - .49 , , , ;j e ^,., - 1 e..,.,.. 3 . % A.- !IS 124B GATE SKIRI' !%QUE PLATE . :; e. ,- . .. . e *. . . . ~ . . . . I .. %, .. i ( . r 'g t - , , ,3.; f sy < k .> ,,. ~, , ;-g. . . ' .. . e F tr !. y 2.,tf. t .v , ,'*; , , t' e vl,'. ,(;; y. . yf ';q - - *' ., ' y ' ' ') L y... 1,y . . ,Q: ,r g 9; V.,' m+' , .Vfs ? . ' e iv, - l,sis-.;l, '.[g'j"h*I.p)t fi ', l ' 'l;; ' i;* ' 'l p)* - , f' a / . i , . ,. -r * * , ,, W i ,~ Jve.. \ . , . '- . . e- \ . , - . . .,.',4.., j :., \ .t t , . ,A [' ~ ,t - .g' . 6,.. .], e r. , ' _ .w ,, _.L* . , 4 . . .,,s . ' , l ' g. l i- - ' <- er , ! E.O. 25504-001 E.R. 7934 1 AITDIDIX G SERIAL 10. 506158 UlTID MS.MVAAAl24-B TAG 2MS-V602B O , R - ' +'9xt.
- z. ..
~ { : r .. , '5; ,- g. , "5 N 3 (yt; ' k; .' y {f
- f. : l l N.. . :- h .
N'b A,'s t)\ 4 ' A ,; , : i ut s i ,t y.. -s 'r fW.. ~~ J . ; <. . . way . . . MS 124B SD3{Dir STOE GALLI 2G 'IOP 5-y _ s - s , ,~ ' i , : '*s Q4. , 16: ,. ;f s ,) , 18 '; s ..' . f. ) ,j ). ((p, l. ,. h ib ~ x.j; ,- t M- ', , I ke ' < s.. k u. X . '<J S.a1 , O MS 124B SlDE GALLI 1G 'IOP SlKNi (OFDi STICKE) l E.O. 25504-001 E.R. 7834 l 4 AFFUiDIX G 2 _________.,,--.,-,,_-___._.._-m , _ . . _ _ _ , , . _ . _ SERIAL 110. 006158 UTID MS.M'EM24-B , Tid 2MS-V602B l l m gy*)m. ,, '; ?. . .! . -.G :' r +n. p- , n -. v.;m ., ( '. ' ) . * ,f
- v>' N .I 4
.g> r ,. q; . (l).9lWf lst a;.l~ (Q d.}lf{ "?. gI "' - O' }$ _ ' {bi~ usy ;j Fe r," .. ,'Ggf.4 - ,dify: %, JV!,s.. l 1]kii -(n.Y:;ill,, 5 l jij, g.?:@pfI".:,,;;rthl y ; ~ /* f.y ~ %yyt;; .c ' b , ); W.g... ; y f n (4 Ei,,s;- t e n -wI-gj 1 C M C.;; p-li ; l; , JW g- p . , ~ ? .y a. ;3x c . , .g 4 m,. , , f. , .7, y . c .py ,d+r A n ~ c' -, w s ;. . ' gb?;. p ew <.,,A 1,% MWs;.,,,, . S, a m.. ', s #7., - s s.. 4 ' i, - ct , 's s !!S 124B S!!OE (21?D) SlidilliG G7d.T TUG Oli D TI'Itti e l 1 %. l f. W 4' - 'i 9, %.'.." u, . . ' \ ..k i , Q, { ' 3 d), , ,. s s '. v _ "e, , t 1 .i lG 124B SilOE SilGlIl1G G/d.LI!1G Oli ICI'IE(1 OF S!!OE E,0, 2550;-001 E.R. 7834 AITDIDI.. G SERIAL 110. 506158 UllID lG.!WAAA124-D i TAG 21G-V602B fu ' ~ t 4'y;, .A.10)F' y?g c s. e , y ., , { i;(I(fj' .y
- i %,t k l$'d;
., q w) ni: -}, , . ' , : ,D * , ,1 a;8M spa ji .,' '. ': ., . , i f;.h U', , J.I f , /J ). ac:.;r s - S . . ., t J g .' . f$5 , , . - . . . * #c~.n;l~,; . , Qs k, '- , \ , . ' # , s' : ;, J (.\ , [. . / '* (_ . , ( O lG 124B SIDE SilOWI11G GALLIllG O!! 'IOP OF Sii0E j'e , A i {'{id \ u ? , k,r;ii9.- ; ~' . 4 .Q 'i: ; ' i j j 4*.s 'j Si ,i ;l, <-- E.O. 25504-001 E.R. 7834 IJFDIDIX G i l SIRIAL 10, 506158 i U? TID FG.t!VAAA124-B TAG 21G-V602B ye .r i ' . ':It I .L - M J ;.t. ! l . ,a ' ' > }, \ , ,i ' W-)y %, y' ,j +. ' q'. , s.,- ,e ' ,p , < . y, g 6. 'in . 'e Y ' s - > .g ~ <.) T 15124B SHOE GALLDU D7FIGI OF SHOE Anu sq O wrp f . - ********i it 'q'.'..mf . g i . c, . 4* ' +fh,,[/',, .s y .N .- . f.. ' ~ 1 - - ,2 db . k- g ~ [' N C q. $ .gi r . ,, ' - ? * '-4.- di6 [%. . . ,, ~<.. + n ,.c, ' Ta n , i 1 + F' ! .' *-. , 'k[ -
- 3. . - >.;,
5 ' l O FG 124B STD4 TOP OF PACKDG IDX AREA-SURFACE UlDDITATIONS CAUSED BY IWiDLUG E.O. 25504-001 E.R. 7834 APFDIDIX G SERIAL 110. 505158 1.'ITID IS.!E\AA124-B TAG 215-V602D jf ' ^ ^ ' b F ~ e ' >l., 15.' g J \x *RV,) , - 'wm:n ; . -gg; '1ff f . ~ 'L ' . x, . \l,V a; . .4 . . . V 9; .A o , <, it t 4- ?.l,. t(ig s !.1 4 !y,s ~ L ' ' - ~.. - - yg . 6-) 4. !G 1248 'IOP OF GNIE SKIRT PAIL 5-E.G. 75501-001 E.R. 7834 AriUTDIX G i t o l r l l I i ) i t i i l j i i HMOGRMHS OF COGQENIS I Mi1V MXEL D2 PRS MSIV SERIAL No. 506158 ! LNID MS.MVAAAl24-B j DG 2Mi-V602B O n~ux a l
- I i I
i i t i J 1 1 3 -i 1 b
- O i
E.O. ?.5504-001 E.R. 7834 i 1 . . . - - , . . . ~ _ - . - . - _ . . . - - . - - _ , . _ , - , , , . , . , .. - - - - , . - - , - - . 1 SERIAL 10. 506158 l l UtilD MS.!WAAA124-B TAG 10. 2MS-V602B O l l - t.c 3 'p i,dhbl -<c f.h , ,,-;g . . O MS 124B TEST SAMPIE (SKIRT RAIL) i ; i a l l l , 1. Y ^ R. j :- 4., , O CD;,xr u. _a E.O. 25504-001 E.R. 7834 AFFDIDIX G l SERIAL 10. 506158 UNID 14S.MVivM124-B TAG 10. 2MS-V602B
- O Ha \
SE MEAF~ ToFo F NAIL r-MS 324B VARICUS RETAINIIM B'GT FAILURE SURFACES-SD24DTP S'GRT (, )' , ,ga,/ ; , 1 :i: ll u , l q, lll 4; ' "=
- /.
- [ %
- 4 1 f
khl l $? (% g:; 4 ?sq n".,qix ; g ) o m L liS 124B TEST SEr-UP FOR D3LT SHEAR TEST E.O. 25504-001 E.R. 7834 APFDOIX G l SERIAL 10, 506158 i UlTID MS.MVAAA124-B l TAG 10. 2MS-V602B l O : l l I ~ tt .. . 1 * \= l. . = ggy - e ' ' . e . , - 1 >~. -* " \ s ,, . n O lE 124B VARIOUS RETADTilM BDLT FAILURE SURFACES-SEG1DTI SKIRT 'r OL b -- * \; ] ~. - p ., " l [ s p. l I ' I .~ A .v..~,.. . O . E.O. 25504-001 E.R. 7834 AFFDIDIX G l SYSTEM SERVICE INC (SSI) AND LPirL PRELIMINARY INVESTIGATION OF BROKEN GUIDE RAIL ASSEMBLY OF MSIV-124B (May 20, 1988) I. INTRODUCTION: The broken guide rail assembly with screws was sent to Ma' ial Evaluation Laboratory (MEL) at Baton Rouge for metallurgical evaluation of the broken assembly. II. NETALLURGICAL EVALUATION: A. Photomacrocraohv Photomacrographs of the guide rail assembly were taken. Figt:res 1 thru 12 depict the failed assembly and the screws which held it together. In Figure 1 the rail assembly is shown with the remains of the cap screws. The screws were numbered 1 thru 9. The ra11 assembly is broken at the screw #6 position. Figure 2 shows the side view of the rail. The dark lines on the rail indicate the rubbing action that takes place when the cam touches the rail during the opening and closing cycles of valve operation. Figure 3 is another end view of the assembly showing that only one screw was still left in one of the rail pieces. The remaining screws were dislodged when the assembly failed. Figure 4 indicates the gouging marks made by the cam on the rail and Figure 5 is the magnified view of these gouge marks near the chamfer for side of the rail assembly. O SPR01045 Page 1 O Figure 6 is the photemacrograph of the failed rail which was broken into two pieces at screw #6. The edges of the fracture surface were severely dented due to the movement of the broken assembly in the main steam piping. The fracture surface is severely oxidized which indicates that the broken piece must have been exposed to main steam temperatures for quite some time. Figure 7 thru 12 shows the fractured surfaces of various screws. The fracture surface details are obscured because of oxidation. Figure 12showthefracturesurfacesofscrew9(ontheleftside) andscrew4(ontherightside). The fractured surfaces of all the screws seem to have similar features. These fractured surfaces exhibit a fair amount of ductility, which indicates a shear overload type of failure. B. Scanning Electron Microscopy Scanning Electron Microscopy was used to evaluate the mode of failure of these screws and the guide assembly. Figure 13 and 14 reveal the dimple rupture type of failure which is I characteristic of : hear overload. These micrographs are taken on the fractured surface of the rail assembly. The fractured surface of the screws #4, #8, and #9 were examined j using Scanning Electron microscopy. Figures 15 and 16 shows the l fractured surface of screw #4. Severe oxidation of the fractured surface obscured the details. However, some areas showed dimple rupture indicating the failure mechanism was shear overload. O SPR01045 Page 2 l Figures 17 and 18 shows the scanning electron micrograph of the fractured surface of screw #9. Areas showing the dimple rupture can be seen in Figure 18. The fracture surface of screw #8 are shown in the figures 19 and 20. Figure 20 indicates slight evidence of dimple rupture. C. Optical Metalloaraphy: The metallographic samples of screws #4, #8, and #9 were taken at the cross section of the fractured surfaces. Figure 21 shows the edge of the fractured surface of scraw #4. The wavy appearance of the fractured surface indicates that the predominant final mode of failure is shear overload. In Figure 22, cracks were present in the root of the thread with some corrosion pitting present. The corrosion of the screw can occur due to galvanic action between the less noble material ie; O the screw. The rail which is martensitic stainless steel is more noble than the low alloy steel screw. Therefore, the low alloy steel would corrode in the presence of moisture. The microstructure shown the Figures 21 and 22 is tempered martensite. The microstructural features for screw #9 are shown in Figures 23 and 24. There are similarities in microstructures between screw #9 and screw #4. Figure 25 indicates the microstructural feature for screw #8. The wavy appearance of the fractured surface indicates that predominant mode of failure is shear overload. Figures 26 knd 27 shows the microstructures of the rail. The microstructure shows martensitic matrix with ferrite stringers. This is the normal microstructure for 17-4 PH martensitic stainless steel. The jagged appearance of the fracture surface (please see theleftsideofthefigure27)indicatesthattherailwasbroken into two pieces due t'o' overload. SPR01045 Page 3 1 O o. aare ess Tes* Rockwoll Hardness tests were conducted on the mounted metallographic samples taken from screws #4, #8, and #9 and the rail plate. The hardness readings are shown in Attachment A. The hardness readings for the plate conforms to the specification l ASTM A693 Grade 630. 1 The hardness values for the screws could not be correlated to any specification, because no data is available for the material specification of the screws. l E. Chemical Composition l The Chemical Composition of screws 4, 9, and the rail plate were : tabulated in Attachment B. The chemical composition of the plate conforms to the O s9ec4<4ca*4oo. asta is93 crade sao. i The chemistry of screws 4 and 9 conforms to AISI 4130. However, no ; data is available on the material design specification of the screws. III. DISCUSSION: The results of scanning microscopy and optical microscopy indicate that the major failure mode is shear overload. However, the following items could have synergistic effect on the failure mode. a) Improper torquing of the screws, b) Misalignment of the rail assembly to the skirt. c) Galvanic type of corrosion of the screws. d) The severe gouging action of the cam on the rail assembly l could ultimately increase the loading cor.dition on the screws. l (SeeFigure#5) O SPR01045 Page 4 Further evalue. tion of the following items is required to prevent the future failure of the guide rail assembly in the NSIVs. a) Replacement of screws with a better corrosion resistant material. b) Redesign of the skirt assembly, c) Proper installation of the skirt assembly ie; proper torquing requirement of the screws and proper alignment of the rail assembly to the skirt. Further investigation on the above mentioned items is presently being conducted by WKM. O l l 1 O SPR01045 Page 5 ) 4 % w l ......... .....--.. = : _ . Figure 1 - Photomacrographic View of the Guide Assembly. O 1 (n WW _ =:k a ~~,- 1 - s .,. . - . - . - - -i--.. _ O Figure 2 - Side View showing the marking done by the Cam. SPR01045 Page 6 r i s O 5 -i ' -;kh,[jjYhhh.'")f- .
- h. . - _-_ _ _ y... a
... _ _.-_ -. ' ~ _ ^ . . - 4 1* d i., I i .................=_ , , _ _ - Figure 3 - End View of the assembly I O SPR01045 Page 7 1 -----;, T % . . ,. + % , _ %m; ., -~._ 4,6 ) s?T ?.2 , ,,.x ygt . * , ?. ~ b,. ,. pw. .= - -(,M *\ , ts. 4 , .g*sg' 4., CNJ 'H . ; - 'q ' z. _'Q- 1 ;, . ,.hT ^ QZ -.:vtIr w w 4;l;."_' .ed g .lat_% Jig 7A;wdn A*. * ' Ijill llllIll llllll1 lillIll(IlllIll IlllllIlIlllIII IIIIIIIlIIII Figure 4 - Plan View of the chamfer end of the rail D , i $4 - ~ :n 'l ! ?]) l . .s t %n,$ l \ l
- $ ~ r \
V:L Tyq
- l
+... . l Figure 5 - Magnified Plan View of the chamfer end 'O SPR01045 Page 8 o ' i l i e ll1 lll lll~T[I lll Tjl lll ll1 Igj p incites 90H4 1 .- 2 ~ din s ~ . _ _ . . + - ~ , _ _ ,_ Figure 6 - Failed surface of the guided assembly at the location of screw #6. J , 'O SPR01045 Page 9 ~ ~ ~~ ~' ~ ~- _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ e- , l in====== ~ \ ' imm m mummmmme 'O I_ m summme i e m imm:en I i I a-, Figure 7 - macrograph of the failed area of screw #8. Q l 4 I l 1 t 1 I Figure 8 - Macrograph of the failed area of screw #8. D SPR01045 Page 10 1 O ,9 . . .:n f, . t. ; . , . s g ,s. ..... . l's ' -/. ' V & ..h. ,/ ,'1. .. N , . - '
o(. 'j .' _ q g. :, ~ )) j < .. . *%e) - l ^- - I . i < I s .g ' ' 3 s , .. ..- y ~ g yy l-g .. . ;- k ... . ~ Figure 11 - Failed area of the screw #7 l O SPiiO1045 Page 12 u -, . . . ? f I tes . 601.-W 1 > Figure 12 - Failed area of screws #4 and #9. O l 1 D SPR01045 Page 13 g ' ~ }fk '?!' "f _'- J >:' j' $ w- -[ .f .' , '? '$ . ', s ,f' .~,fy'lf. , _.-l 9 , -) ' ^ '
- i, ? { >l, l ';Q,,[ ,
^ ~ .. . .. . g c y ' '1 ;, f '. g.i g,* '" ' f.' - ,2 - ,, y t' ,4 ' [ ' ~ . .j'd:, 't ' p, '< ,' - t .i j,' .' .ph - (; .< ,g / . h t' lg.Wh ;ik ,.a' 40X - Magnification Figure 13 - Scanning Electron Micrograph of the failed portion of the guide assembly near screw #6. Strong Q evidence of overload failure mechanism. t l . l \ .. ,, .d . . . f h f.f , f.b,,' s ' g; ,, <(' % 'T.8-Figure 14 - Higher magnification of the failed portion of the guide assembly. Failure is due to overload. SPR01045 Page 14 <3 .L N - D , 'Y ./'- hl;g'"yyggfj .[ f' ff$h"e . .? b . _. a_q$he4, ?. , 3 ,, I. ^ .r 3 y%. -/r ,._s.s - ,a . ,'2.5 ,, . J, . A, ' ,-). T. . / s ; ,. j - .. h r1 - i' . . ., 4 _( ;.1 :
- s. 7./ (
f . . ; i. :af.. . gn,; >; t,. L, ,.,j,
- w. -
Figure 15 - Scanning Electron Photomicrograph of the fractured surface screw #4 - severe oxidation of the surface obsecured details. Screw #4 - 20X Magnification ( .h ^;. .[ ff, f9 s t - 3;.. . f, .7 s L.y' ? .- [.$r : . , 4 .- r . ll 1, *t ,, . ' _ . . ..sj:g;J' ,,.,, ; 9 ,,.& e
- )
g.- u :- . w y < ... 17 1 .S.. a r.: v, . .. . 9. , s q ;. .~ - ' .a/ ( ' ) <7.,, ,.-) . ;' i ' 3 7 .,t., . ;+s .,
- v. -
^, g, y. si,6 .. '2 . < - y .# Uz.6'_[45 -,&'aY.*,le., & ;g,ry '-. .. f-' 'i- .. h . Y' h.,; ?. b Y 5)f$ ; & j.. q : g : Q h ; j. . f S.4[h ,? $1 f ': 0' , .N ' h l .. l%l, : i . Figure 16 - Scanning Electron Photomicrograph of the Q fractured surface of screw #4. Dimple surface indicated the evidence of overload failure - 100X Magnification. SPR01045 Page 15 l l P . ., 7g . . . . . . . t , ' g .:] . , ~ %. . O , l ~ } w . .. t. . . .. - , ; ;; z L- '-' ~-.y fg ' 'z ,7P:-D." .,. ,' '- - ~2 'K&Q Y ,%q" 3 c ,c'?-y'.*~~,'f'f-k.:y .. ~& . ,x ,sy my. :._ ,; 7 ry; -:. .;~ _ .y 25X Figure 17 - SEM Photomicrograph of the fractured surface of screw #9 - 25X. b .. ~ .. . v. ; ... n .- 'n 4 .'......i
- n. i., . *r -Q , r h , ,,
W-
- W.y'l k.'. ' G ' , 4,
_ f J'_f Q& ,,s ; Q ' ' w ~- E; -:p g*,.T ' _ . 5- , p\. -.. . . . . . . . . g. j:. . $3 ^ y? -} f?pr_
- -[ l.K '.. _
. . Vy : . .- <-v < q .;;. - .s t, ~
- ..-%R.. ,. (.
-*g, . W- ,.., ,e r . - - - ll, '. T k %, .( %- .. ))+. . . - ' - l er . R "- -:;,,, g , . pqi. ' ; , y / ', .f<1L.- em <* % , =~L }.. '.} . 3/5" . /. t- '.4. [ & T [.'v 3 %iN Y ' " $' %4, . . ,.. n h j-Figure 18 - SEM Photomicrograph of the failed surface of .O the screw #9. Evidence of ductile overload mode of failure is visible (Dimple rupture). SPR01045 Page 16 l l .,wo "' n ' .. ; ~- c ;- b.E.,M.hp *~ .Ma - . i g~c,. l O q~- x.: ,x.. y " 4% 1 l l I i 1 l l l l i ... l Magnification 25X l Figure 19 - SEM Photomicrograph of the screw #8 failed surface. .m <- pg -y g..y ~ ,- - o: + . . -) , - ,_ :
- 4. [ -,-,_ ^' .sy .
. p , g . , re,, .p--- - , ;r 'k ^ ) j}'?_- ) 2 2 .. - .- f . ~ gg _. & . 9 l9 ^ i-f5h h ,r .
- .. -),e- ~e h .,f y ^
9. f J* ' . . .{#', ryx; p}[ .}~* ;.Q . , nj.m.-. > 46. ' , . . ' lY' - -~ J $1agnification200X Figure 20 - SEM Photomicrograph of the screw #8 Dimple mode indicates overload is the basic mechanism. O SPR01045 Page 17 1 l .r . O " . .,,:.M ' D ' N Fracture .,4'. ~ 'Jjr' ". .;fJifh. ... ' h*. fy " Surface j 3 )* ; . , '[, , , ' -}:,.. y. ,_ >, - u- .. e t .,,' ' .<5 - g, * . . '.. , ,.' .;- ~' f - . ' . . j .. ! .y ~ ]' * ^ *
- 1. :,; ,j::Q:;.;,A,l ha js,g:/^.
i s ii.;.:. G b7 @ M 4 ? R W Wj.9 . 9 e. . Magnification 100X Figure 21 - Optical Photomicrograph of the mounted sample. Microstructure is tempered martensite wavy appearance of the fracture indicates ductile overload mode of failure. Screw #4. O x mm ?ll**fl@;Lt$m+gg@Mg59 M. gid '..h '. . Q:+Q..;- g i )."f';;:re , k ' ,, ;+ ' . 17 g i* Ma [h4 . . . M ks $f[;., Y5 'ik .R. "M29 l l . L f l ,w
- 5. CC'~ d
.w Magnifiestion 150X h Figure 22 - Optical Photomicrograph of the root of the threats of screw #4. Secondary cracks can be seem. SPR01045 Page 18 i \ q /.*- jfE t, h f @ dig Eh@. M . 2 hv <+. ::.w ; typ;&;ni:;. -Q&ty,;97.;.9,g ~, , e , :s . w f\il !.d & _ .gWs e ;u 't. 3 ^ $h[h'0 ; kg,.; df ' [ Np h j .k'IV'I43.Ed[526$h:4t//cb,'FM)t. ,% M*,Eid, d 4 150X Figure 23 - Optical Photomicrograph.of the faiied screw #9. Wavy , appearance of the fracture indicates ductile overload is the primary mechanism. <o _ . _= g .. c .. .. . . . , , ,. .,, .!f. bf. ,,.kr 1 ; , :::;, .'.3 . ...,,..,: . F4?hhlN,h),,.. . ._t.-lp, ;- +
- s ,
, 1 i - , . . 4 ~ 150X 'O Figuro 24 - Optical Micrograph of the root of the thread of the screw #9. Secondary cracks are noticeable. SPR01045 Page 19 (O 's 1 '/ . t . <..j : 4 <; *dG e' , Fracture * ?.b' . Surface '.;. ' a~A!-!!i " .d,.6j . ', : , . !I. cl ,)dl' ~..,. -,. '.; : ~ ':.' .. Lla)t*y*y:'rss?c l ,y, .,
- ..k <r.,,yy ;. ;.-. :2 . y.
4,.}.~k;c;.u . f- O, t. * -r . . ,}, /60 x Figure 25 - Optical Photograph of the failed portion of the screw #8. Wavy appearance of the fracture indicates ductile overload. D SPR01045 Page 20 ' b o, 4 % - . $3 l$ M i. Et 150X m - ' 4 (%y - av N? "hf $$b i 'N' .-W.e%s7/Madh;fiSMek;r;;wds ,$dndist$n.$ dee Figure 26 - Optical Photomicrograph of the failed area of guide assembly. Microstructure: - Martensitic matrix with ferrite phase. 'V jpp, . JS .NmW"7' q. dl?M-v0TCJO4 . E 'C q'-'g . , r.9v. qpwkPv~L. y cir.i ? 30 s.%./[h.~[4l,y.3,' 8;,% d ., s M "N.h" %.h, ~&c. % ?.jjlu*:l' .(; f Q&q:f{f ,i,g(,{ Q: a . '~:k.a.up(aq;h. v gyjyhc -a e,
- c. w lu.
qasg( v
- s + - . r
.U ~~ i 'cp$4 ' "g . a {,: . . .i udse? 3 , . ;-M,@m!2fw$MMy/ 6 c; f< H;4gy.e 4+ #h? ' .;'fll[ft, :.M .02rVB '"Ai&~..&
- m. -
ag . sm . . b;;r,,,ra4,v g . -;%eg;"4;..n . ?" h.Y*h 150x *
- r. ,- ~
Figure 27 - Fracture surface indicates wavy appearance indicates overload mode of failure. SPR01045 Page 21 O ATTACHMENT A SAMPLE HARONESS READINGS AVERAGE HARONESS ~
- 1. Bolt #4 38.8, 39.9, 39.5 39.4 HRC
- 2. Bolt #8 38.9, 37,5, 37.8 38.1 HRC
- 3. Bolt #9 40.5, 40.2, 40.5 40.4 HRC
- 4. Plate 32.3, 33.5, 33.6 33.5 HRC
- 5. Plate (At 36.0, 32.5, 31.2 33.2 HRC Fracture) 1 l
1 1 O SPR01045 _O ^11^Casent B ELEMENT BOLT 4 BOLT 9 PLATE Carbon 0.32 0.33 0.026 Sulfur 0.012 0.011 0.020 Phosphorus 0.010 less than 0.067 0.01 Silicon 0.23 0.23 0.55 Manganese 0.70 0.70 0.47 Chromium 0.96 0.92 15.2 Nickel 0.019 0.018 3.9 Molybdenum 0.23 0.22 0.22 Aluminum less than less than - 0.01 0.01 Copper 0.01 0.01 3.0 Vanadium less than less than - 0.01 0.01 Titanium less than less than less than 0.01 0.01 0.01 Tungsten less than less than - ] ( Niobium 0.01 less than 0.01 less than 0.18 0.01 0.01 Cobalt - - 0.078 Iron Matrix Matrix Matrix NOTE: Data reported in weight percent. O SPR01045 1 v,; .: . ; :w.pa y . .y%q,,;;;p: ~ ; . . : ,, ~ yta ..t . ,.. ,, O ~ / \ M \/ \/ E L \ / O MATERIAIB EVALUATION
- LABORATORY' 17696 PERKIMS ROAD . BATON ROUGE.1.OUISLANA . 70010 (504) 29H070 V.
8 i O I MATERIALS EVALUATION LABORATORY y INCORPORATED 17695 Perkins Road g Baton Rouge. Louisiana 70810 reieonone <504) 2924070 MAY 11, 1988 M.E.L. PROJECT 47875 METALLURGICAL EXAMINATION OF FLAT-HEAD, SOCKET-DRIVE O LOW ALLOY STEEL SCREWS CONTRACT #C30752 l l PREPARED FOR: 1 1 LOUISIANA POWER & LIGHT COMPANY P. O. BOX B RILLONA, LA 70066 ) O N ' I f_ MATERIALS EVALUATION LABORATORY kg'pQ> INCORPORATED 17695 Perkins Road ) Baton Rouge, Louisiana 70810 Teleonone (504) 2924070 a' I May 11, 1988 Mr. J.B. Perez Louisiana Power & Light Company Waterford 3 SES - Nuclear P. O. Box B K111ona, LA 70066 RE: MEL Project #7875 Metallurgical Examination of Flat-Head, Socket-Drive Low Alloy Steel Screws Contract #C30752 BACKGROUND: Samples of flat-head, socket-drive machine screws were submitted for examination. The screws were identified as being a low alloy steel insidematerial and they a large valve. had been used to attach a guide plate represented: Three categories of screws were "good" screws which had given no indications of g problems; "bad" screws during nondestructive which had exhibited examination; and, "failed" evidence of "cracking" apparently twisted of f during removal. It was requested screws which had that the screws cracking. be chemically analyzed and examined for the presence of RESULTS: Specimens representing the "good" and "bad" screws were prepared metallurgically for examination. (Note: The amount of material available with the "failed" screws was minimal. M r. Perez elected to use this material for carbon determination.) The basic microstructures were considered representative of a quenched and tempered high-strength, low-alloy steel. A careful examination the material.of both specimens revealed no evidence of cracking in The "apparent" cracks indicated during NDE of the "bad" screws were revealed to be elongated, undercutting pits. Figure i shows a cross-sectional view of one of these pits. U 1 1 Mr. J.B. Perez s- May 11, 1988 Page Two A tabulation of the chemical analysis results follows: "Bad" Screws "Good" Screws "Failed" Scruws ELEMENT B-1 3-2 G-1 G-2 F-1 F-2 Carbon 0.34 0.31 0.33 0.30 0.31* 0.33* Sulfur 0.006 0.007 0.004 0.007 Manganese 0.09 0.71 0.81 0.70 Chromium 1.03 1.04 0.11 1.05 Nick,1 0.030 0.027 0.10 0.028 Moly:sdenum 0.25 0.23 0.25 0.25 Silicon 0.19 0.097 0.15 0.16 Phosphorus 0,010 0.003 0.004 0.010 Aluminum <0.010 <0.010 0.031 (0,010 Copper <0.010 <0.010 0.14 < el . ? 10 Niobium <0.010 0.010 <0.010 <0 .11 0 Titanium <0.010 <0.010 (0.010 (0.f40 Vanadium 0.010 <0.010 <0.010 <0.010 Iron Matrix Matrix Matrix Matrix
- Insufficient sample for furtter analysis.
O1 -Data reported in weight percent. Respectfully submitted, Claude R. Mount General Manager Reviewed By: ! u v - - Date: $5//' 2 8 ' CRM/kkr NOTE: The specimen (s) prepared for and remnants of this analysis will be discarded after 30 days unless written i instructions for alternative handling are received. l (3 %-) \ l 1 i > FIGURE 1 4 C- .- ', . '.. 3 8 * - }Y.'5 . .:n- :. :. .::-
- s'. .
- ,M1 .'r-
. . . s .. . .,!';g A I I FIGURE 1: Photomicrograph of a cross-section through a region Indicated to be cracked by previous NDE methods. The defect is ! ) in fact an elongated, undercutting pit at the root of a thread. ) (Magnification 100X, Nital Etch) .i I i l l I i MAIN STEAM ISOLATION VALVE PROJECT MS 124A l l l NEL Reoort Sucolement 5 Backaround i As explained previously, the remaining valve, MS 124A was disassembled and the skirt and rails were still intact; however, some of the cap screw heads were j missing. The segment side skirt had 3 broken screws and the gate seat skirt had ! 5 broken screws. Soes of the cap screw heads were broken at the head to shank i interface and some were broken at the skirt to rail interface. ! A visual examination revealed that some of the screw heads were misaligned { with respect to the screw holes. At one end, the rail extended at least 1/16 of an inch beyond the skirt. The part number on the rails indicated that the segment side rails were identified as the gate side rails. If the rails were f switched, this would possibly explain the misalignment, , { Nondestructive Examinations The capscrews were difficult to remove, and it was necessary to weld a nut to the top of each screw and remove the screws with an impact wrench. The screwswereexaminedbythefluorescentmagneticparticle(MT)methodandfive of them had linear indications along the head to shank area, t O . WRK030347 l - . _ . .__ l l Chemical Analysis, ThescrewswithnoMTindications(labelledGfor"good")andtwoscrews withindications(labelled 8for"bad")werechemicallyanalyzed. The results i indicated that three of the screws were within the AISI 4130 chemistry specifications and one was a carbon steel screw (AISI 1030) Two other screws which had failed upon removal were also tested, but there was only enough material to do a carbon analysis. Chemical results are included in the Material Evaluation Laboratory (MEL) !!eport. Metalloarachic Analysis Specimens representing the good and bad screws were sectioned and prepared for metallographic examination. The structure of the screws was a tempered ! martensite microstructure indicative of quenched and tempered low alloy steel. O A thorough exam of the screw revealed no evidence of quench cracking, or other material defects occuring from the fabrication process. However, severe corrosion pits were found at the root of the threads which may have appeared as ! crack-likeindicationsduringtheMTexamination(SeeMELReport). The most severe corrosion pitting was found in the plate area of the screws which was the part without thread engagement. Tha pitting may have been , accelerated by moisture accumulating in the gap between skirt and rail. I U WRK030347 O Conclusion Since the screws were low alloy, and in some cases carbon steel, and rails I i were stainless, the galvanic action would accelerate the pitting corrosion. The l corrosion pits provide crack initiation sites which would lead to failure by the combinationoffactorsasdescribedintheWKM(CooperIndustries)reportand the preliminary investigation report. O l O . 1 WRKO30347 _. . - . _. . - .___.._. .- - ..._ - -._ _ - --. - - - . .-. - -}}