ML17214A311
| ML17214A311 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 04/27/1983 |
| From: | Kaza R EBASCO SERVICES, INC. |
| To: | |
| Shared Package | |
| ML17214A312 | List: |
| References | |
| FLO-8770.114, NUDOCS 8307190165 | |
| Download: ML17214A311 (99) | |
Text
(
1SOLATZON/?UR.E VALVE ANALYSXS 48"-RXA BUTTER"LY VALV" BLOCKED FT 40 r
Project Site St. Lucia Nuclear Power Plant Unit r 1 Customer Engineer Florida Power
& Light Company Ebasco
- Services, Inc.
Specificat'on
".7o.
Original Purchase Order NY-422237 Original P att uob No.
D-44376-01 (Old.Job Nos.
D-27270
& 7-4491-1)
'alve Tag Nos.
1-FCV-25-1, 2,
3, 4,
5, 6
General Arrangement Dr wings E-2184 Rely.
- 5 Cross Section Drawing C-1784 Rev.
Prepared bv:
Date:
Date.:
~ ~ I P Reviewed by:
Dat:
0 IJ AD+ )
Certif'ec; ky:
l~ (n/J(/~M.
01'L'LIIIIIIIIIE(
'v l pg(
PF!0("EK.OPAL vF
~I O~
~<IIIIllll'L>
M' Bso7ieo165 830715 PDR ADOCK 05000335 P
I.
Introduction CONTENTS Pacael II.
Considerations'II.
Method of Analysis A.
Torque Calculation B.
Valve Stress An'a'ysis C.
Operator Evaluation IV.
Conclusion l2 V.
~ Attachments (l)
Input Documents (A)
New Pressure vs.
Time Graph (B)
Customer/Engineer
Response
to Request for Inf'ornation (2)
Valve Assenkly Stress
- Report, (3)
General Arrangement and Cross-Section Drawings
0
I.
Introduction This report, is a re-analysis and re-evaluation of the St. Lucie Unit Cl containment isolation/purge valves based a new containment pressure time curve and delay time furnished by the owner/engineer and Pratt current analysis approach.
J ~
This report supercedes the previous report issued "or this unit, date'd July 9, l980..
The current analysis is based on the assumption that the first incidence o+ sonic low coincides wi+h the critical valve disc angle as a worst case condition as explained in the report.
This supports the presence of out of plane elbows immediatelv upstream o
the valve w'th worst case valve flow direction and worst case valve closing direction from the full open to the closed position.
II.
Considerations The NRC guidelines for demonstration of operability of purge and vent valves, dated 9/27/79, have been incorporated in this evaluation as follows:
A.l. Valve closure t'me during a LOCA will be less than or equal to the no-flow time demonstrated during shop tests, since fluid dvnamic effects tend to close a butterfly valve.
Valve closure rate vs. time is based on a sinusoidal function.
- 2. Flow direction through valve contributing to highest torque;
- namely, flow toward the hub side of disc if asymmetric, is used in this analysis.
Pressure on upstream side of. valve
)
as furnished by customer/engineer is utilized in calculations.
Downstream pressure vs.
LOCA time is assumed to be mors< case.
- 3. horst case is determined'as a single valve closure of the inside containment valve, with the outside containment valve fixed at the fully open position.
- 4. Containment back pressure will have no effect on cylinder operation since the same'ack pressure will also be present at the inlet side of the cylinder and differential pressure will be the same during operation.
- 5. Purge valves supplied by He'nry Pratt Company do not normally include accumulat'ors.
Accumulators, when used, are for opening the valve rather than closing.
'orque limiting devices apply only to electric motor operators which were not furnished with purge valves evaluated in this report.
0 I
I
r, 768.
Drawing or written description of valve orientation with respect to piping immediately upstream, as well as. direction of valve closure, is furnished by customer/engineer.
In this report worst case. conditions have been considered; 90 elbow (upstream) oriented 90 out-of-plane with respect to valve shaft, and leading edge of disc closing toward outer--
wall of elbow.
E fects of downstream piping on system back pressure have been covered in Paragraph A.2 (above).
/
The Pratt purge valve analysis program was developed for indicated LOCA cond'tions using existing Pratt model test data.
During 1982, Pratt undertook additional model testing to consider alternate valve/piping configurations, such as elbows immediately and two diameters upstream of the valve wi'th valve ha=t "out-of=plane" with respect to elbows, flow from flat and arch side of disc, clockwise and counterclockwise disc closure, and disc diameter to thick-ness ratios.
The dynamic torques determined by the model tests were in all cases lower than calculated by the Pratt purge valve analysis program.
B.
This analysis consists of a static analysis of the valve components indicating if the stress levels 'under comb'ed
~ seismic and LOCA conditions are less'han allowable stresses and/or 0.40 x yield strength for sh ar (non-Code components) in Table 1 of the materials used.
A valve operator evaluation is presented based on the operator manufacturer's rating versus the calculated LOCA-1 induced fluid dynamic torques.
I Sealing integrity can be evaluated as follows:
decontamination chemicals have very little effect on EPT and stainless steel seats.
Molded EPT seats are generically known to have a
cumulative radiation resistance of l x l0.
rads at a maximum
.incidence temperature of 350 F.
Zt is recommended that seats are visually inspected every 18 months an'd be replaced periodically as required.
Valves at, outside ambient temperatures below 0 P, if not properly adjusted, may have leakage due to thermal contraction of the elas orner;
- however, during a LOCA, the valve in"ernal temperature would be expected to be higher than ambient which tends to increase seal'ng capabil'y after valve closure.
The 'presence of debris or damage to the seats would obviously impair sealing.
XXX.
Method of Analysis.
C~AL Determination of the structural and operational adequacy of the valve assembly is based on-the calculation of LOCA-induced
- torque, valve stress analysis and operator evaluation.
A.
Torque calculation The torque of any open butterfly valve is. the summation of fluid dynamic torque and bearing friction torque at any given disc angle.
/
Bearing friction torque is calculated from the following equation:
T>=PxAxUxd where P =pressure differe..tial, osi 2
A = projected disc area normal to flow, in
'U = bearing coefficient of friction d = shaf t diameter, in.
Fluid dynamic torque is calculated from the following equations:
For subson'c flow RCR >
l ~
- l. 07 (approx. ).
P2 3
TD=D xCTlxP2x For sonic flow K
x F in Pl R
P2
.T =D,xC 2xP v
3 K
x F 1.4 RE RE TD ='luid dynamic torque, in-lbs.
F
= Reynold number factor RCR = critical pressu e ratio, (f +)
)
Pl
= upstream static pressure at flow condition, psia P2
= downstream static pressure at flow condition, psia D
= disc diameter, in.
CTl = subsonic torque coefficient C
2 = sonic torque coe ficient T2 K
isentropic gas exponent (1.2 for air/steam mix) disc angle, such that 90
= fully open; 0
= fully 0
0 closed Note that CTl and CT2 are a function of disc angle, an ex-ponential function of pressure ratio, and are adjusted to a 5" test model using a function of Reynolds number (size factor).
Torque coefficients and exponential factors are derived from analysis of experimental test da a and correlated with analytically predicted behavior of air oils in compressible'media.
Rnperical and, analytical findings confirm that subsonic and sonic flow'.conditions across the valve disc have an unequal and opposite.effect on dynamic torque.
Specifically, increases in up-stream pressure in the subsonic range result in higher torque values, while increasing Pl in the sonic range results in lower torques.
'\\
Therefore, the point of greatest concern is the condition of initial sonic flow, which occurs at a critical pressure ratio.
The effect of valve closure during the transition from subsonic to sonic flow is to greatly ampli y the resulting torques.
In fact, the maximum dynamic torque occurs when initial sonic flow occurs coincident with the critical disc angle (approximately 70 from the fully closed position).
The following computer outputs summarize calculation data and torque results for valve opening angl'es of 40 to 0
and 0
0 50 to 0
I I
D-44376-1(D-27270)
'ORQUE TABLE
/
21 / 83 JOB:FLO.r"MR/ST.LUCIE SAT.STEAN/A.R HIXTURE MITH 1.4 LBS STEA?i PER 1-LBS A:R SF'EC.GR.=
.738255 tiOL.i)T.= 21,3872 KAPA( ISEHT.EXP.)= 1.19775 GAS COHSTAHT-CALC.
SOHIC Sr'EED(iiOVIHG t'iiXTR. ) = 132!.45 FEET/SEC AT'30 DEG.
F,'=
72
~ 1972 FOR 47.125 t(AX ~ TORQUE IHCLUDE Si E
Er r c C i (REYttOLDS HO. ETC) AF'P...
X 1.23234 INCH BASIC LIHE i.D..
ALL F'R SSURES USc D: STATiC(TAr")F'rESS. -ABSOLUT i P IHCL ~ RECOVERY PRESS
~
(TORQUE) CALO'S VALIDITY:Pi /P2)1. 07; VALVE TY"E:
DISC SI:E:
SHAFT DIA.:
BRG.
COEF.
Gr
~ RCTH.:
SEATIHG r"ACTOR:
IhLET PRESS.VAR.iRAX.:
tiAX.A.iG. r'U RA: =":
CRIT.SOH'C F'U-90DG:
VALVE It LET DE?tSITY:
SYST'ti CONI'iTIOHS:
P Ir" Iti-PIPE-GUT tiIHI?(Uti 0.75 DiAi":.
48"-RlA CLASS 75 46.71o IHChES OFr Sr T ASYiitiETRIC DISC 4.75 IHCHES 5.00000E 03 i5
~ '
4954 F SIA 146252.
C.""Hi 256392 S r<<l 14094.6 LB/tiIH 32040.
L /?<<IH AT 17.185..!tLc,T rPSIA
- 9. a3715E-02 LB/FT 3-!'1IH.. 11975 L3/FT "3-t(AX.
At".D-AIR/STEAA iiIXTURE ScRVICE 8 -230 DEG.F Pir E DOU!iST";,'EA!'i FROH CENT.LIHE SHAFT.
Pi ABS ~
F'RESSURE(ADJ. )r OL' "S TIRE/PRESS. TRAHSIEttT CURVE ~
"-5 IH.?1OD='QUIV AHG' Pi P2 D"='
F'PPR).'.r"SIA r"SIA r"SI RAT 40 34.20 15.89 18.31 35 36i ~ 03 14 82 21+21 30 37.29 14.77 22.52 25 38.08 14.73 23.34 20 38.35 14.72 23.63'5 38.73
'14.70 24.03 10 39.79 14.70 25.09 5 41.23 14.70 26.53 0 42.50 14.70 27.'80
.VALU RESS.
.465
.411
.396
~ Dp7
.384
.380
~ 36P
.357
.346 ES------ACTUAL SIIE VALUc.S---
rLOM FLOiJ TD TD+TH T r l(E (SCrFti)
(LB/t(IH) --IHCHLBS-- TD-TB-TH 256391 14094 98358 244 98114 192212 10566 75956 294 75661 151252 8314 46882 334 46548 106836
.5873 32432 366 3206 64902 3567 22990 405 22584 35997 1978 9442 459 8982 18215 1001 5529 538 4'991 5741 315 4055 597 3458 0
0 33877 565
'33311 (LOCA)
SEC.
2.30 2.73 7
0P 3.33 0 ~ ii 3 ~ 50 3.74 4.10 4'2 SEATIHG
~
BEARIHG +
HUB SEAL TORQUE (H/H)=
33877 IH-LDS e
0 DEG.
r D-44376-l(D-27270)
TORQUE TABLE
/ 21 / 83 JOB:FLO.PL)R/ST.LUCIE SAT.STEAH/AIR tfiXTURE UITH 1.4 LBS STEA'Pf r ER 1-LBS AIR.
SF'EC.GR.=
.738255 tfOL.UT.= 21.3872 KAPA(ISEHT.EXP.)= 1.19775 GAS COHSTAHT-CALC.
SOHIC SF'D(tfOV.'HG tfIXTR.)= 13 1.45 FFET/SEC AT 30 DcG.
R= 72.1972 tfAX~ TORQU" IHCLUDES SIZE EFFECT(.".
YHOLDS HO.ETC) Ar'PX ~
X I.
017 FOR 47.125 IH CH BASIC LIHE i.D.
ALL PF.'ESSURES USED: STATIC (TAr')PRESS. <<AB OLUTE > F'HCI...'ECOVcRY r'.'ESS.
(TOROU )CALC'S VALIDITY:Pi/P2>1.07; VALVE TYrPE:
DISC SiiE:
SHAFT DIA.:
BRG.
CO-F.
OF 'FRCTtx.:
SEATIt!G FACTOR:
IHLET PRESS.VAR.MAX.:
tfAX~ AHG.FLGU RA:E!
CRIT.SOHIC FLOG-90DG:
VALVE IHL T DEt!SITY,'YSTE)f COt!Di.'GtiS:
P IF'E Itt-P IPE-OUT-tfIH:hUtf 0.75 D:A.'i.
48"-Rih CLASS 46.718 It!CHES 4.75'NCHES 5.00000E-03 15 43.9o62 PSiA 205383.
Crtf,'6 44/ f '
o o/t".J l ~
9.6 715E-02 LB/F
<<C/v OFFSET ASYtftfETRIC DISC 0052.
SCF,"i'97'93.
LB/i'fIH AT 18.6503 iHL=T r' T 3 HIR
.1 3892 LB/FT"3 t"'AX AHD-AIR/STEAti tfIXTURE SERVICE P.
230 DEB.F P Ir'E DOfthSTR-AH'ROtf C" iNT. It!E SHAFT.
Pi ABS.
PRESSURE(ADJ
~
)FOLLOUS TitfE/PRESS.TRAHSiEHT CU;:.E.
""5 IH.tf AH 6 LE rP1 F'2 APPRX.PSIA PSIA 50 34.20 16.11 45 36.65 15.02 40 38.44 14.94 35 39,77 14.84 30 40.59 14.78 25 40.87 14.74 20 41.0o 14.72 15 41.59 14.70 10 42.36 14.70 5 43.24 14.70 0, 43.97 14.70 ODEL EQU V.V" DELP PRESS PSI RATIO 18.09
.471 21.63
.410 23.50
.389 24.93
.373 25.82
.364 26.13
..361 wean
<<0
~ d1 e3JO 26.88
.354 27.66
.347 28.54
.340 29.27
.334 UES----ACTUAL SI-E
'VALUc.S
- "'ft FLOM TD (SCFtf)
(LB/t!It!) --INCH 360051 19793 158416 382171 2 i 009 170270 278237 15295 139113 9159o5 11835 o50ci 162435 8929 57109 114078
. o271 37718 6o243 3806 26492 38682 2126 10382 19385 1065 5809 6092 334 4113 0
0 33907 TB~TH LOS 205 200 3l1 3
~ 8 474 407 447 508 en6 642 595 TIr'.E TD-TB-TH 158211 170003 13880 9'i? 42 g 6<<<<g 37310 2o045 9873 52 3471 33311 (LOCA)
SEC.
. 2.30 2e?4 3'2 3.42 o ~ 0<<
3.69 lj ~ I 0
- 3. 95
'4.26 4;65 5.08
- SEATIHG + BEARIHG + HUB SEAL TORGUE (l'i/M)=
33907 IH-LBS e 0
DFG.
B.
Valve Stress Analysis The Pratt butterfly valve furnished was specifically designed for the requirements of the original order which did not include specific LOCA conditions.
The valve stress analysis consists of two major sections:
- 1) the body analysis, and
- 2) all other components.
The body is analyzed per x'ules and equations given in paragraph IPB 3545 of Section III of the ASHE Boile and Pressure Vessel Cod The other components are analyzed per a basic strength 'of materials type of approach.
For each component. of interest, tensile and 'shear stress levels are calculated.
They are then combined using the formula
'max = X(T1+T2)'+
='
2 (Tl+T2) "
il (Sl-.'2) where Smax
= maximum combined stress, psi Tl
= direct tensile stress, psi T2
= tensile stress due to bending, psi Sl
= direct. shear stress, psi S2
= shear stress due to torsion, psi The calculated maximum valve torque resulting from LOCA cond'tions is used in the seismic st ess analysis, attachment N2, along with "G" I
loads per design specification.
,The calculated stress values are compared to code allowables if possible, or LOCA allowables of 90t of the yield strength of the material used.
C.
erator Evaluation Model:
Bettis T520-SR2 Rating:
200,000 in-lbs at ull open and closed positions only 143,774 in-lbs at 68 125,000 in-lb at 45 (minimum rating)
Maximum valve torque:
98,358 in-lbs (valve blocked at 40
)
The maximum torque generated during a
LOCA" induces reactive r
forces in the load carrying components of -the actuator.
Since the LOCA induced torque calculated in this analysis for valve disc opening of 40 or less is lower than the absorption rating of the operator, it is concluded that the Bettis model furnished is structurally suj.table to with-stand combined LOCA and seismic loads as defined in th's analysis when'locked to a maximum from the closed position.
Torque calculations were also opening angle of 40 P
performed 'for-closing from the 45 and 50 open position which indicated that the operator manufacturer's rating was exceeded.
I
IV.
Conclus ion:
The calculated stresses of the Valve components (valve blocked at 40
) for combined seismic and LOCA conditions as shown are less than allowable stresses and/or 0.40 x yield strength for shear (non-Code components)
Table l of the materials used.
Zt is concluded that the valve structure and the valve actuator are capable of withstanding combined seismic and LOCA-induced loads based on the calculated torques developed in the analys's for closing from valve disc opening angles of 40
'or less.
O z
z s
i I
(
ATTACHHENT THIS ANALYSIS IS IN ACCORDANCE NITH PART l OF PRATT PROPOSAL DATED FEBRUAR'5 24, '1983.
ATTACHHENT 1B CUSTOMER/ENGINEER RESPONSE TO REQUEST FOR INFORMATION
Purchase Order Removed from Report
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SEISMIC ANALYSIS FOR 48 INCH NUCLEAR PURGE VALVE
TABLE OF CONTENTS LIST OF FIGURES NOMENCLATURE
SUMMARY
TABLES STRESS LEVEL
SUMMARY
FREQUENCY ANALYSIS SUMi~1ARY VALVE DIMENSIONAL DATA PAGE 1
16 25 26 STRESS ANALYSIS INTRODUCTION FLANGE ANALYSIS BODY ANALYSIS DISC ANALYSIS SHAFT ANALYSIS'9 33 34 39
,40 SHAFT RETAINER ANALYSIS DISC HUB ANALYSIS SHAFT BEARING ANALYSIS THRUST BEARING ANALYSIS BOTTOM COVER ANALYSIS OPERATOR MOUNTING ANALYSIS TOP TRUNNION ASSEMBLY FREQUENCY ANALYSIS 42 44 48 50 58
0
~
~
LIST OF FIGURES TITLE PAGE VALVE BODY SPATIAL ORIENTATION 31 BANJO ASSEMBLY 32
'PRESSURE AREA ANALYSIS CROSS-SECTION IN BODY 36'ISC HUB BLOCK THRUST BEARING ASSEMBLY
- TOP TRUNNION MOUNTING TRUNNION BOLT PATTERN
'OPERATOR BOLT PA'TERN TOP TRUNNION ASSEMBLY 46 51 53 56
POllHHC>> "'
Q'he nomenclature for this analys's is based upon the
~
nomenclature established in. Paragraph NB-3534 of,Section III of the BSHE Boiler and Pressure Vessel Code...- Nherc the nomen-clature comes directly from the code, the reference paragraph or figure for that symbol is given ~:ith the definition.
For i
symbols rot defined in the code, the definition is that assigned by Henry Pratt Company. for use in this analysis.
(
ANALYSIS NOblEHCLATUPE Effective fluid pressure area based on fully corroded interior "ontour for calculat'ng crotch primary membrane stress.(NB-3545.1(a)),
in>.
Am Hetal area based on fully corroded interior contour effective in resisting fluid force on Af (NB-3545.1(a)),
in'l A2 A3 A4 A6 A7 A8 Tensile area of thrust bearing adjusting screw.
Tensile area of bottom cover bolt, in2.
Shear area of bottom cover bolt, in>.
E Tensile area of trunnion bolt, in>.
Shear area of trunnion bolt, in Tensile area of operator bolt, in2.
Shear area of operator bolt, in Tensile area of hub retainer bolts.
Alo Shear area of hub bolts.
Tensile area of hub bolts.'12
'13 B2 Shear area of thrust bearing. retainer bolts.
Tensile area of tnrust bearing retainer bolts.
Unsupported shaft length, in.
Bearing bore'iameter, in.
A factor depending upon the method of attachment.
of head, shell dimensions, and other items as listed in NC-3225. 2, dimensionless (Fig. NC-3225.1 thru Fig. NC-3225.3).
Cb Stress index for body bending secondary stress resulting from moment in connected pipe.
Cp C3 Stress index for body primary plus secondary
- stress, inside surface, 'resulting from internal pressure (NB-3545.2 (a)).
Stress index for thermal secondary membrane stress resulting from structural discontinuity.
Stress index for maximum secondary
'membrane plus bending stress resulting from structural discontinuity.
MALYSXS NOt<ENCLhTUPt".
C6 C7 Product of Young's modulus and coefficient of linear thermal expansion, at 500oF, psi/ F(NB-3550).
Distance to outer fiber of disc for bending along the shaft, in.
C Distance to outer fiber of disc for bending about the shaf t, in.
Inside diameter of body neck at crotch region (NB-3545.1(a));
in.
-(
Dl Valve nominal diameter.,- in.
D2 Shaf t diameter, in.
D3 Hub retainer bore diameter.
D4 Thrust collar outside diameter, in.
D5 Thrust bearing bolt diameter, in.
D6 Cover cap bolt diameter, in.
D7 Trunnion bolt diameter, in.
D8 Operator bolt diameter, in.
D1 p Diameter of thrus t bearing,. ad jus ting s tud, in.
Dl1 Outer diameter of trunnion, in.
h!odulus of elasticity, psi.
Bending modulus of standard connected
- pipe, as given by Figs.
NB-3545.2-.4 and NB-3545.2-5; in3.
N
~1/2 x cross-sectional area of standard connected
- pipe, as given by Figs.
NB-3545.2-2 and NB=3545.2-3, in.
Natural frequency of respective
- assembly, hertz.
W3gx Seismic force along x axis due to seismic acceleration acting on operator extended
- mass, pounds..
F N3gy Seismic force along y axis due to seismic acceleration acting on operator extended
- mass, pounds.
W3gz Seismic force along z axis due to seismic acceleration a'cting on operator extended
- mass, pounds.
Gravitational acceleration
- constant, inch-per-second Gb
'Valve body section bending modulus at crotch region (NB-3545.2 (b)), in3.
ANATiYSIS NOMENCE. ATURE
(
6<
Gt Valve body section area at crotch region (NB-3545.2(b) ), in2.
Valve body section torsional modulus at crotch region (NB-3545.2(b)), in>.
g Seismic acceleration constant along x axis.
Seism'ic acceleration constant along y axis.
Seismic acceleration constant along z axis.
hg Gasket moment arm, equal to the radial distance from the cente line of the bolts to the line of the gasket reaction (NC-3225), in.
, H2 H3 H5 H7.
Hg Z3 Disc hub key height, in.
Top trunnion bolt square, in.
Bottom trunnion bolt square, in.
Operator bolt square, in.
Operator bolt circle, in.
'ctual body wall thickness,
-n.
I Disc area moment of inertia or bending along he shaft, in Disc area moment of inertia for bending along the shaft, in Moment of inertia of valve body, in 4 Z~
I7 Moment of inertia of shaf t, in Disc area moment of inertia for bending of unsupported flat
- plate, in4.
- s Moment of inertia of top trunnion plate.
Distance to neutral bending axis for top trunnion bolt pattern along x axis, in.
.J2 Distance to neutral bending axis for top trunnion bolt pattern along y axis, in.
J5 Distance to neutral bending axis for operator bolt pattern along x axis, in.
Distance to neutral bending axis for operator bolt pattern along. y axis, in.
~
K Spring constant.
AWALYSlS t:,OMENCLATURE Distance of bonnet leg from shaft centerline, in.
K2 Thickness of disc above shaft, in.
K3 Length along z axis to c.g.
adapter plate, in.
K<
Top trunnion width,'n.
KS Top trunnion depth, in.
K6 Height o top trunnion, in.
Ll Valve body face-to-face dimension, in.
L2 Thickness of ope ator housing under trunnion bolt,. in.
L>
Length of engagement of co0er cap bolts in bottom trunnion, in.
Length of engagement of trunnion bolts in adapter plate, in.
7r LS L6 L7 Ls Bearing length, -'n.
Length of shaft after retainer groove, in.
Length of engagement o
adapter bolts in adapter platy, in.
Length of, engagement of adapter bolts in top trunnion, plate,
. in.
L9 Length of engagement of stub shaft in disc, in.
Ll Disc hub key length, in.
m Top trunnion weld height.
Reciprocal of Poisson's ratio.
Mass of component..
M M
h H
Ng (g Zo+gsYo), operator extended mass seismic bending moment about the x axis, acting at the base of the operator, in-lbs.
P N3 (gxZo+gzXo), operator extended mass seismic bending moment about the y axis, acting at the base of',the operator, in-lbs.
N3 (gxZo+gyXo), operator extended mass seismic bending moment about the z axis, in-lbs.
Nx+FyTS, operator extended mass. seismic bending moment about
'the x'.axis, acting at the bottom of the adapter plate, in-lbs.
My+FxTS, operator extended ma s seismic bending moment about the y axis, acting at the bottom of the adapter plate, in-lbs.
ANALYSIS NO/tFNCLATURE
~s Bending moment at joint of flat plate to disc hub, in-lbs.
Permissible number of complete start-up/shut-down cycles at'r./100 r/hr/hr fluid temperature change rate (NB-3545. 3).
NA Not applicable to 'analysis of the system.
Number of top disc pins.
Number of operator bolts.
N3 Pd Pr Number of trunnion bolts.
Design pressure, psi.
Primary pressure
- rating, pound.
Ps Standard calculation pressure, psi.'e Largest value among
- Peb, Ped, Pet, psi.
Peb Ped Pet
'econdary stress in crotch reg'on of valve body caused by bending of connection standard pipe, calculated according to NB-3545. 2 (b), psi.
'I Secondary stress in crotch region of valve body caused by direct or axial load imposed by connected standard pip'ng
.calculated according to NB-3545. 2 (b), psi.
Secondary stress in crotch region o
valve body caused by twisting of connected standard pipe, calculated according to NB-3545.2(b), psi.'
m
'General primary membrane stress intensitv at crotch region, calculated according to NB-3545.1(a), psi.
~ Pm Q
Primary membrane stress intensity in body wall, psi.
Sum of primary plus secondary stresses at crotch resultin'g from internal pressure, (NB-3545.2(2)), psi.
QT
~ Thermal stress in crotch region resulting from 100 r/hr fluid temperature change 'rate, psi.
Haximum thermal stress component caused by through wall temperature graduent associated with 100oP/hr fluid temperature change rate (NB-3545.2(c)), psi.
(
QT3 Haximum thermal secondary membrane stress resulting from 1'00oP/hr fluid temperature change rate, psi.
Maximum thermal secondary membrane plus bending stress re-sulting from structural discontinuity and 100oF/hr fluid temperature chango rate, psi.
Distance to bolts in bolt patte"'n on hub block, in.
ANALYSIS HOHENCLATURE Distance to bolts in bolt pattern on hub block, in.
Distance to bolts in bolt pattern on hub block, in.
r Distance to'olts. in bolt pattern on hub. block, in.
Q5 Q6 Q7 Dis"ance to bolts in bolt pattern on hub block, in.
Distance to bolts in bolt pattern on hub block, in.
JY Distance rom shaft cen erline to disc plate, in.
Mean radius of body wall at crotch region (Fig. 4~3545.2(c)-1),in.
Inside radius of body at crotch region for calculating Qp (NB-3545.2(a)), in.
r2 Fillet radius of external surface at crotch (NB-3545.2(a)),in.
R4 Disc radius, in.
R5 Shaft radius, in.
R Mean radius of body wall, in.
m R
Radius to gasket in cover cap, in.-
. Distance from shaft centerlj.ne to retaining bolt of thrust bearing.
Sm S n As'sumed maxim m stress in connected pipe for calculating Pe (NB 3545
~ 2 (b) )
g 30 g 000 psi.
Design stress intensity, (NB-3533), psi.
I Sum of primarv plus secondary stress intensities at crotch region resulting from 100oF/hr. fluid temperature change rate (NB-3545.3), psi.
S 1
Fatigue-stress intensity at inside surface in crotch region resulting from 100oF/hr. fluid temperature change rate (NH-3545.3), psi.
S 2
Fatigue stress intensity at outside surface in crotch region resulting from 100oF/hr. fluid temperature change.
rate (NB-3545.3), psi.
S(1) through S(68) are listed after the alphabetical section.
Hinimi>m body wall thickness adjacent to crotch for cal-culating thermal stresses (Fig. HB-3545.2(c)-1) in.
minimum body wall thickn"ss as determined by C.'C.1678, in.
T, ANALYSIS I'OMENCLATUPE Maximum ef fective metal thickness in crotch region for calculating thermal stre,ses, (Fig. NB-3545.2(c)-l), in.
Maximum magnitude of the difference in average wall 2
temperatures for walls of thickness te, Te, resulting from 100or:/hr. fluid temperature change rate, oP.
0 Tl Thickness of cover cap behind bolt head, in.
T2 Thickness of adjust'ng screw head, in.
T3 Thrust col1ar re taining pla te thickness, in T4 Cover cap thickness, in.
T5 Adapter plate thickness, in.
Ts Maximum required operating torcue for valve, in-lbs.
T9 Shaf t retainer thickness on hub.
Tl0 Bottom cover plate thickness.
Tll Top trunnion wall thickness.
Tl2 Thickness o
top trunnion plate.
.'Thrust bearing coef icient o friction Bearing friction torque due to pressur'e loading (shaft journal bearing).
Bear'ing friction torque due to pressure loading plus seismic loading (snaf 4 journal bearings)
U6 Vl Thrust bearing friction torque.
Distances to bolts in bolt pattern on adapter plate, in.
V2 Distances to bolts in bolt pattern on adapter plate, in.
V3 V4 Distances to bolts in bolt pattern on adapter plate, in.
Distances to bolts in bolt pattern on adapter plate, in.
Total bolt load, pounds.
Wl W,
3 W4 Valve weight, pounds.
Banjo weight, pounds.
Operator weight, pound
'Adapter plate weight, pounds.
ANALYSIS NOMENCLATURE Weight of disc, pounds.
Eccentricity of center of gravity of operator extended mass a'ong x axis, in.
Y Eccentricity of center of gravity of operator extended mass along y axis, in.
Z0 Eccentricity of center of gravity of operator extended mass along z axis, in:
Maximum stat'c deflection of component "in.
Z7 Z 8 Distance to edge of disc hub, in.
Thrust bearing stud diameter, in.
ANALYSIS NOHEHCLATURH S
(1)
= Combined bending stress in disc, psi.
S (2)
= Bending stress in disc due to bending along the shaft, psi.
S (3)
= Bending stress in disc due to bending about the shaft, psi.
S (4)
= Combined stress in shaf t, psi.
.S (5)
'= Combined bending stress in shaft, psi.
S (6)
= Combined shear stress in sha t, psi.
S (7)
= Bending stress in shaft due to s'eismic and pressure loads along x-axis,. psi..
S (8)
= Bending st"ess in sha.ft due to seismic load along y-axis, ps 3. ~
S (9)
= Torsional shear stress in top shaft due to operating torque,. psi.
S(10)
= Direct shear stress in shaft due to s'eismic and pressure loads, psi.
Shear tear out of retainer in shaft groove, psi.
S (12)
= Shear tear out of shaf t groove, psi.
S(13)
= Bearing stress on retainer and.groove, psi.
S (14) t S (15)
Tensile stress in retainer bolts, psi.
Bearing stress on hub kevway, psi.
S(16)
= Shear stres's on key, psi.
S(17)
= Combined stress on hub block bolts,. psi.
'S(18)
= Combined tensile stress. on hub block bolts, psi.
S(19)
= Shear stress in hub block bolts, psi.
S (20)
= Shear tear out of shaf" through hub block, psi.
S(21)
= Compressive load on shaft bearings, lbs.
S (22)
=. Bearing stress on thrust collar, psi.
S(23)
= Shear stress in adjusting scr-w head, psi.
S(24)
= Combined stress in adjusting screw,.psi.
ANALYSIS
~LlOMEHCLilTURE
(
s(25) s (26) s (27)
S (28)
Direct tensile stress on adjusting screw, psi.
Torsional shear stress on adjusting screw, psi.
Shear stress in adjusting screw threads, psi.
Combined stress ip retainer bolts, psi.
s (29) s (3o)
Tensile stress in retainer bolts, psi.
Shear stress in retainer bolts, psi.
S (31)'hear tear out of thrust bearing bolts,, psi.
s(32) s(33)
Shear stress in cover plate, psi.
Shear tear out of bolts through tapped holes in trunnion, psi
~
-(
s(34) s (35)
S (36) s (37) s (38)
Shear stress in cover cap bolts due to torsional E ~
Direct tensile stress in cover cap bolts, psi.
Combined stres" in cover c p, psi.
- loads, ps i.
Shear tear out of cover cap bolt head through bottom cover cap, psi.
Combined stress in cover cap bolts, psi.
s(39) s{4o',
s (4l) s (42)
Radial stress in cover cap, psi.
Tangential stress in cover cap, psi.
Shear stress in cover cap, psi.
1 Shear tear out of trunnion bolt through tapped hole in trunnion, psi.
S (43)
Bearing stress of trunnion bolt on through hole in trunnion plate, psi.
S (44)
~ s (4s)
Bearing stress of trunnion bolt on tapped hole in adapter plate, psi.
Shear tear out of trunnion bolt head through top trunnion plate, psi.
S (46)
Combined stress in trunnion bolt, psi.
S(47) ='irect tensile stress in trunnion bolt, psi.
s(48)
Tensile stress in trunnion bolt due to bending moment, psi.
ANALYSIS NOflr,"NCLATUPE s(<9) s (50)
Direct shear stress in trunnion bolt, psi.
Shear stress in trunnion bolt due to torsional load, psi.
s {5l) s (52)
Shear tear out of operator bolt head through adapter plateg psi Bearing stress o
operator bolt on through hole in adapter plate, psi.
s (53)
Combined stress in operator bolts, psi.
S (54)
S (55) s (56)
Direct tensile stress in operator bolts, psi.
Tensile stress in operator bolt due to bending monent, psi.
Direct shear stress in operator bolts, psi.
(
S (57) s(5s)
S (59)
'S (60)
Sheaz stress in operator bolt due to torsion, psi.-
Combined shear stress in the top trunnion plate welds is a maximum due to seismic and torsional loads, psi.
Shear stress due to operator eccentricity, psi.
Torsional shear due to operator eccentricity and operator torque, psi.
s(6l)
,Combined stress in base of trunnion b'ody due.to combined
- bending, torsion and seismic loads, psi.
S (62)
S (63) s(6C)
S (65)
Direc" tensile stress, psi.
Bending tensile stress, psi.
Direct shear stress, psi.
Torsional shear stress, psi.
S (66)
Combined shear stress in top trunnion to shell weld is a
max'imum due to seismic and torsional loads, psi.
S (67)
S (6S)
Shear stress due to operator eccentricity, psi.
Torsional shear due to operator eccentricity and operating torque, psi.
Sl./l lHAT(V 'J'AULl'NTl:.ODl!CT3 ON
(
Xn the following page,,
thc pcrtincnt data for the butter-'ly valve st c"'nalysis is tabula(cd in three categor's; 1.
Stre Levels for Valve Components 2.
Natural Frequencies of Components 3..
Valve Dimensional Data In Table 1, Stress Levels for Valve, Components, the following data is tabulated:
F Component Name Code Reference
( when app'licable)
Stress Level Name and Symbol Analysis Reference page Haterial Specif ication
(
Actual.Stress
~evel Allowable Stress Level The materi" 1 specifications are ta!:cn rom Section ZI of the code when a'pplicable.
Allowable stress levels are Sm for tensile stresses,and
.6 Sm for shear stres es.
The a'lowable levels are the arne whether the calculated stre s is a combined stress o"
results from a single load condition.
Sm is the design stress intensity value as defined in Appendix I, Table 1-7.1 of Section III of the code.
In Table 2, 'Natural Frequencies of Valve Components, thc following data i" tabulated:
Summar Table Introduc tion Component t'lame Natural Frequency.Symbol Analysis Reference Page
~ Component Hate ial Natural Frequency P
E 1
Xn Table 3, Valve Dimensional Data, the values for the pertinent valve diriensions and parameters are given.
15
PQ<JQs 21 27 Stre. s j.cvel Summary, Frcauency Analysis Summary and Valve Dimensional Data sheets have been assembled at the beginning of th>> rcport ubmittal.
They are located directly behind the c.esign re-ricw record for the corresponding production ord.r.
16-17-18-19-20
~
i
~ I I ~
~ ~
I I
I I I
~ ~
e I
~ I
~
~
~
~
e I I I
~ I I I I I
I I
~ I I
I ii
~ ~
I
~
I
~ ~
~
I
I
~
~ ~
~
~
I ~
I ~
~
~
t ~
0 ~
~ ~
r
~
~
s ~
~ ~
~
~
~
~
r
~
~ ~
0 0
0
TABLE
~
~
STRESS LEVELS XLVE COMPONENTS
- Oa lPONENT'perator Mounting (Cont. )
CODE REF PARAGRAPH SYMBOL & NAME Combined s tress in operator bolts Combined shear stress in top trun-nion plate S (53)
S (58)
REF.
PAGE NATERIAL ASTM A-540 Cl. 1 Gr.
B21 ASTM A-516 Gr.
60 STRESS LEVEL, PSI I eu7+
ALLOski iBLI STRESS LEVc PSI
- 1. 5S 49500
- 1. 5S 22500 Combined stress. in bise. oC trunnion body Combined shear stress in top trunnion to body shell weld S (61.)
S (66) 55 57 ASTM A-350 Gr.LFII ASTM A-516 Gr.60 4 OQO
- l. 5S 26250
.6S 90OO
Table 2
NATURAL-FREQUENCIES OF VALVE COMPONENTS Component Name Natural Frequency Symbol Re f.
Page Material.
Natural Frequency (Hertz)
BODY F l 58 ASTN A-516 Gr.
60 BANJO N 2 59 hSTH h-479 Type 304 Ia 7<-
COVER CAP FN 3
59 ASTM A-126 Cl.
B I Gl 6
JOB NUhl3ER:
OPERATOR iMOUNTING:
.DIMENSXONl(L DATA
.(g-gg~~g$ ~~I.))VALVE SIZE:
P =., ~
OPERATOR:
Am A'2 A3 A6 A7 D2 D3 D4 D6 D7 DS E17 '..
Hg I~
I4
~ )chal l0 10 Agg A~2
~
A~~
B~
B2 CP C2 Fx F
F Gb 6
Kg K2 K4 K6 L2 L3
, 7 c
l, 7.
L7 LS L~
lp 1, l wS x'2 O.S V2 U3 W2 N3 M
M M
M e'.
Pg P
te m
hT2 T2 T3 T4 0
Xp Yp Z p Z7 ZS 0~ miscg~c~~
Q1 l.5'0 12 U4 Q6 UG V1
STANDARD STRESS REPORT FOR 48"-RZA CONTAINMENT/ISOLATION PURGE VALVE NETH ADAPTER PLATE NOUN ED CYLINDER OPERATOR
Al!hJ'JY!3 1 S ZN'I IEOI)(ICTZOII Descri)lcd in 'tlic following pages is the analysis used in verifying t)ic structural adequacy of thc main elements of. the air purge butterfly valve.
The analysis is structured to comply with Paragraph ND-3550 of Section ZIZ of the ASHE Boiler and Pressure Vcs el Code '(hereafter re erred to as the code).
Xn the analysis, the design rules for Class 1 valves are used.
Since the requirements for this class of valve is much more explic' than for either C" ass 2 or 3 design rules.
The design rules for Class 2 and 3 are exceeded.
by the rules for Class 1
valves.
The air purge valve is designed in accordance with Coae Case.
1676 of the code.
Valve components are analyzed under the assumption "hat the valve is either at maximum fluid aynamic torque or seating against the mavimum cesign pres ure.
Analysis temperature is 00 F.
Seismic accelerations are simultaneously applied in each of three mutually pe"pendicular directions.
Seismic loads are made an integral part of the analysis by the inclusion of the ac eleratioa constants g, g
g The x'
z'ymbol g
g g
repre ent accelerations'n the x, y and z
-x' z
direction respecLively.
These. directions are defined with rc-spcct to the valve body ccntcrcd coordinate system as illustrated in 1'igur. l.
Specifically, thc x axis is along the pipe axis f the z axis i
~ a'long thc sh. ft axis, and the y axis is mutually perp.ndicul'ar to the x and z axe.,
forming a right hand triad
'~ri th t)balll.
29
Valve orientation with respect to gravity is taken into account by adding the appropriate quantity to the seismic loads.
The justification for doing this is that a gravitational load is corrpletely equivalent to a lg seismic loaQ,.-
The analysis of each main element or sub-assembly of the 0
butt rfly valve is described separately in an appropriately titled I
section.
In addition to containing sketches where appropriate, each section contains an explanation o. the basis for each cal-I culation.
%here applicable', it al o contains an interpretation of code requirements as they apply to the analysis.
Figure 2 is a cross-section view of the butter ly valve, and its associated components.
'Detailed ketches are prov ded Khroughout the repo t to clearlv define'the geometry.
30
~
~
~
~
~ ~
~ r
~ r
~ ~
0
~
~
PlGui",L'
- ESSEI'TInL rI:rTurES OI'A;IJn ASSL>>BLY
\\
~
~
~
r SIRFT'P ETA I IIER S L I ("S I iITO GROOVE P!l0 IS B OLTE0 TO fIUB DLOCIi.
~ r',
OI)EERATCR I'"-Y':"iY
~ C rl.
C;C(. ~(
GROOVE
~r' If(I@PS(f l($/
~
' f, ~ ~
l C
~
0;"
s ~
(S~Iqg.
'tr'i' J(
~
~ C u BLOCii C.'!'
'l1 ~
HUB B LOCI:S Sht',FT R."TilI IIER BOLTS SIBF (
RETP I I!EPS DISC BOT10H SYUS 5 llew~
32
~I'LA14Gl AilALYSIG The flange analysis is in accordance with Appendix II, Para.
VA-56 of Section VIII, Division I, of the AS&1K Codes ior Pressure Vessels and AV.";lA C-207.
l 33
(
DODY AtIRT.'ISZH The body analy i consi"t of calculations as detailed in Paragraph liH-3q40 of Section III of the code.
Paragraph NB-3540 is not highly oriented. to butterfly valves as related to various design and shape rules.
Therefore, certain of the design equa tions cannot be directlv applied for butterfly valves.
Nhere inter-pretation unique to the calculation is neces ary, it 's explained'n the sub-sectioh containing that calculation description.
/
Figure 3 il"ustrates the essent'al eatures of the body geometry through the trunnion area of the valve.
The symbols used. to de ine specific dimensions are consistent with those used in the analysis and with the nomenclature used in the code.
(
1.
Hinimum Body Pall Th'c!;ness Paragraph NB-3542 gives minimum body,wall thickness requirements for standard pressure rated valve The actual minimum wall thickness in the purge valve occurs behind the seat ret'aining screws.
2.
Bouv Shape Rules The air purge valve meets the requirements of Paragraph H
ND.-3544 of the code for body shape rules.
The external fillet at trunnion to body intersection must be greater than thirty percent of the minimum body wall thickness.
3.
Primaz'g lit'mbra>>o Stress Duo to Internal Prcssure Paragraph Nl3-.35~>5.1 dcf ines the mar.imum allowable stress
'n the neck to flow passage junction.
Zn a butterfly valve, this corresponds with the trunnion to body sholl junction.
Figure 3 shows the geometry through this section.
The code def ine the stresses in the crotch area using the pressure area method.
The equation presented is found in paragraph NB-3545.1.
Pm = (Af/Am +.5)
Ps Applying the code rules to the crotch region results in a membr-ne stress considerably less than i~ applied to the'region not conta'ning
~he trunnion.
The trunnion incrc'ases the metal area (Am) v:hich decreases the A~/Am ratio and reduces the result.
For
- a. sectLon not con-taining'he trunnion, the fluid'area to-metal area atio
'(Af/Am) reduces to the body inside radius to the shell thickness (Pe/kg) since the depths are the same.
The resulting membrane stress equation i then:
Pm =
(Rm/Ilg +.5)
Ps This equation results in the highest stressed area and complies with the intent of the code.
4.
Secondary.
Stresses A. Bocly Primary plus secondary stre s due to intex;nal pr cs urc ~
35
r l JiriVuVI'rlr I'hlrlrl'h I'Eral'hlr l r) I ri BODY CllOSS - Si:CT IOH Figure 3
~r L
I L-
--- ii A,. L'6
Bod Anal'aragraph ND-3545.?
(a) of Section III of the code defines thc fo -mul".s used 'n calculating this s "ress B.
Qp =C r.i+
r e
Secondary stress due to pipe reaction Para.
HB-3545.2(b) gives the formulas for. finding stress due to pipe reaction:
ed d
= Direct or axial load effect'd Pcb
= CbFbS Den< ing load effect b
get b
= 1oraional load effect
=2F S
Gt Thermal secondary stre.ss--Para.
NB-3545.2(c) of Section III of the code gives formulas for determining Me thermal s=conc',ary "ress"s in the pipe.
where QT 6
26T2 D.
Primarv plus secondary stresses This calculation is per Para.
ND-3545.2 and is the sum of the three previous secondary stre ses:
5.
3S m 8
Q
+
P d+
2O 2
n p
. e valve ~f..-:ti v rcccircmcnta vera.
HD-3545. 3 of section 111 of
'the cocle dcfincs rcquircment for n'rmal duty valve fatiguee The 'iilo~;-.blc stre lcvcl is found from Figurc 1-9.0.
Since thc numb r of cycles is unknown, a maximum value of 2000 is assumed.
The <<13o';:able stl css can then be found from Figurc 1-9.1 for carbon tcr l.
This then gives an allowable stress
l3odv isnulg.: i.." (Cont'cl of 65000 p i.
S 1 = 2/39
+
P F2
+ OT3 = 1.3Q P2=
.4Q
+P ~+ 2Q3 p
eb
539
(
- DISC Dill'.Ji'LSIS Section N13--35)6.2 defines the design requirements of the valve disc..Both primary bending and primary membrane stress are mentioned in this section.
For a flat plate such as the butterfly valve disc, membrane stre s is not defined until the deflection of the disc reaches one-half of the disc thickness.
Since total deflection of the d'sc is much less than one-half the
/
thickness, membrane stresses are not applicable to the analysis.
Figure S shows the disc for the air purge bu"terfly valve.
The disc is designed to provide a structurally sound pressure retaining component while providing the least interference to tlie flow.
Primar.)
Bendin-Stress Due to the manner in which the disc is supported, the disc experiences bencing both along the shaft axis and about the shaft axis.
The combined bending stress is maximized at the disc center where the maximum moment occurs.
The moment is a result of a uniform pressure load.
Combi net S(1)
=
wher e bending stress
'(S(2)
+ S(3)
)
in disc:
S (2)
=
.90413 P
R C7
'3' 4
7 Z4 S (3)
=
. 6666 PR4 C8 3
I3 Bend i ng s tres s due to moment.
along shaft axis, psi Bending s tres doe to moment about shaf t axis, psi 39
S1lh1'T i~N7LLYGXs The shaft is analyzed in accordance with Para ND-3546.3 Section EI'T of the Code.
The shaf t loading is a combination of
- seismic, pr es sure, and'perating loads.
Maximum torsional loading is either a combination of seating and.bearing torque or bearing and dynamic torque.
Columnar 'tres" is not considered in the shaft loading due to its negligible e
ect on the stress levels.
Figure 2 shows the banjo assembly with the stub shafts.
Shaf t, stresses due to pressure,
- seismic, and operating loads:
S(4)
= 5(5)
+ (5(5)
+4 S(6)
)
2 2
Nhere:
s(5) s (7)
(S (7)
+S (8)
)
= combined 2
2 I
(~P'P
+W,g
). 25 B, R, s
2 x 4
m.25R5 bending stress, psi Bending tensile stress due to pressure and seismic loads along x axis, psi s(8) s(s)
. 25Ã2g Bl<
~ 25
')T P~
4 s (9)
+s (lO)
)
Bending tensile stress due to seismic loads along y axis, psi
=
" Combined shear stress, psi s(9)
= T8R 8
5
~5mR 5
Torsional shear stress, psi S(lO) =.- l.333
. 5mR4 P +
. 5H2.(g
+g
) '
2*
2 s
2'.
v 2
wR5
= Direct shear stress p
ps J.
The shaft'retainer assembly consists of the shaft retainer,
. the shaft retainer bolts; and the g ooved end of the stub sha 't as sho~;n in figure 2.
The. shaf t retainer bolts, and shaf t groove are loaded by the seismic force of the disc.'"
Shear tear out of retainer in shaft groove.
/
W g S(ll)
=
mD2T~
2.
Shear tear out of shaf t groove.
3.
S(12)
=
2~z vD3>>
Bearing stress on retaine" and groov'e.
S(l3)
=
4 W g 2
z
~(D-D,
)
2 4.
Tensile stress in "etainer bolts.
S(l4)
=
W2g 4
g
11UB DLOCV. hS."I'.llilIY The hub block assembly cons's of the hub block, the hub block retaining bolt, and the hub block key way.
~
~
1 2.
Bear ing s trcs on the hub key way.
S(lS)
=
R5H1L10 Shear stress on key.
S(16)
=
S RrHlL10 3."
Combined stress on hub block bolts.
(17)S(lG)+(S(1$ )+ 4S(lg))
2 where:
l S(lG)
=
All D
P 2
s N2g 1
(B~+Q4-) Q3 6+ "2 2
2 8 (Ql +Q2
+Q3
)
6
+
8 12 6Q7 Q5" Q6 Q5 +(Q5+Q
)
2 2
Combir ed tensile stress in bolts due to torsional,'re sure and eismic loads.
S(l~)
=.
Pl a
~
cA10 Shear stress in bolts due to seismic load
'Shear tear.'uL. of shaft thru hub block.
mP R<
ah' S(20)
=
2 L (E:~+
. 5D2) g 2
42
F lGUf(C +
1 l
K2
The leave bearings in the trunnion are subjected to both seismic and pressure loads.
mP R< +t 2(g
+g
)
2, 2
2 S(2l)
=
2
= Compressive load on shaft bearing, lbs.
As soon ih I"gure 5,
tho thru"t boaring assomb3.y is located in tho bottom trunnion.
Xt provido restraint, for the banjo in the z directior., assuring that the disc edge remains corroctly positioned to inaintain optimum sealing.
formulas used to analyze the assembly are giver. below.
1.
Bearing stre.,
on thrust collar due to seismic load.
2.
H2g I
S (22)
.785 (D
-0
)
Shear stress in adjusting screw head due to seismic load.
N>g S(23)
=
10 2
3.
Combined stress in ad jus tirg screw.
(24)
S (25)
(S (25)
- - 4S (26)
)
2 2.
Hhere:
Hg
~
S(25)
=
~
A2 16U6 S(26) 10 Direct tensile stress due to seismic load.
Torsional shear stre s due to thrust bea'ring seismic friction torque.
10 4.
Shear "tress in adjusting screw threads due to seismic loads.
N g S (27)
~ 9mD T
5.
Combined stross in rota'ner bolts. due to ci mic loads.
S(28)
=
+
~
2 (S(29)
+
~S(30)
)'
a I.
" l lbVI',L ESSt:tel lr L t <:.AT'"~rS OF TlH<USl'l:Pi(lllG FSSLl'Y
~I VALVE BODY St!AFT
~
~
t
~ (
7'jig)) T
$ fa ~ IJpg
~~
I V
oI l~X) yXp Is/ f
~,
~
~0
~ t r t,Ernie,ttiC SCRF.';I
~
~
~\\
Thrust Boatr.in'hn<.1.,is (Cont'd)
Where W2g.
S (29) 6 Al3 Ten"ile stress duo to seismic load.
6.
U S (30)
Shear stress due to sei"mic load 6 mD>: t 6 R7A Shear tear out of thrust bearing retainer bolts.
W g S(3l)='7
BOTT011 CO'JI.R AlibiJiY S l' Figure 5 shows the bottom trunnion a sembly, including the bottom cover and bottom cover bolts.
1.
Bottom Cover Bolt Stre ses The bottom cover experiences loading from the weight of the banjo anc from pressure loads.
Zn determining tress levels, the bolts are assumed to share torsional and tensile loading equally.
Shear tear S (33) out of bolts through tapped holes in trunnio n.
Ng PR 2
z s
6 Shear tear S (34) 4L
(
out of N g
~
2 z
4Tl (5
- 2. S3)
D bolt heads through bottom cover, psi:
2'p R
2)
D6 Combined stress in bolts, ps i:
s (35)
S (37) 2
+
(S (37)
+
4S (36)
) '
~ Mhere:
S (36).
U
. 70111~
4 Shear stress in bolts duc to torsional load
Bol:io<n Cover. A~nnl.:i.",
Cont'c!
W2g
+
mP R
2 S(37) 4 A3
- 2. Bottom Cover Stresse Tcnsilc stress in bolts due to sei..mic and pressure loads, psi The combined stress using the folio~sing S (39)
+
S (40) 2 in the bottom cover is calculated formulas:
2
( SS(39(
+
S (40)
)
+
4 S(41)
)
Where:
S(39)
=
S (40)
S(41)
=
3 (. 785 (D4+. 25)
P
+W g 2
s 2
z 2
4 m T4.
3(.785(D4+.25)
P
'N2g 2
s 2
z 4
mT m
2
. 785 (D<+.. 25)
P
+ ~g s
z
. m (D4+. 25) T4 Radial Stress Tang en tia 1 S tress Shear Stress
OPERATOR MOUt'Tli'tG Ai~IALYSZS The operator. mounting 'consists of the top trunnion, the adapter
- plate, the operator housing and the bolt connections as shown in Figure 1.
Bolt stresses and localized stress due to bolt loads.
The following assumptions are used in the development of the eouations:
A.
Torsional, direct shear, and direct tensile loads are shared eaually by all bolts in the pattern.
B.
Moments across the bolt pattern are opposed in such a
way that the load in each bolt is proportional to its e
in adapter pla te.
2 2
2 S(42)
=
z+"4 g
+g
+gz
~ >>(
- 'J2
+2 (J2+H2)
Jl +2 (Ji+H2)
.9mL4D7 2).
Bearing stress on through 2
2
(
M +T
+
(F
+F
)
4l.707H7) 4 D T holes in top trunnion plate.
7 l2 3)
Bearing stress on tapped holes in adapter plate.
distance from the neutral bending axis.
I l)
Shear tear out of trunnion bolt through tapped hole 4~70 Hp) 4 4
D7L4 4)
Shear tear out of trunnion bolt heads through top trunnion plate.
2J2 +2 {J2+/la) 2Jl +2(Jl+li2) 2 q
2 2
2 5.2 D7Tl 50
339
5)
Combined stress in trunnion bolts (Fig.
8)
S (46)
S (47)+S (48)
+
((S (47)+S (48) )
+
4 (S (49)+S (50) )
).
2 2
Where S (47)
F +N<g 'irect tensile stress, psi.
- s. (48) 4A5
= +x( 2+"2) 2J2 +2 (J2+H2) 2 2
M (J +H
)
2 2
2Jl +2 (Jl+H2)
Tensile stress due to extended mass bending moment, psi.
(F
+F
)~+
W (g
+
)~
S(49)
=
x 4'gx gv
= Direct shear stress, psi 4A S (50)
=
2 8 '
Shear 'stress due to torsional load, psi M +T
(.707H2)4A6 6)
Shear tearout of operator bolt head through adapter plate.
I s (51)
(M +M )V4 X
V 2(Vl +V2 +V3 +V4
)
2 2
2 2
5.2D8T5
+
Z 4
7)
Bearing. stress on through holes in adapter plate.
I S (52)
M,+TS
.5H7ST5DS Where
'S(54)
=
2' Direct tensile stress, psi.
F
.4A7 S (55)
(M '+M
) V4 Tensile stress due to 2(V
+V
+V V
)
bending moment, psi.
2~
2 4AS
= Direct shear stress, psi.
8)
Combined stress in operator bolts (Fig.
10)
(53)
S (54 ) +S (55)
+
( (S (54 )+S (55) )
+4 (S (56) +S (57) )
)
2 2
S (57 I
=
z 8
= Shear stress doe to torsion, psi.
M +T
.5H78hS 52
P J" Jl p
~ ~
)%5,
'Jz
. TOP TlYUXNIGA BOLl'IYG l'1QUl'c
~
J
~ ~
~
~
53
II Y
~
~
I I
l
(
f I
lJ~
Ti/l
/-'/
V~
Yr ovv.assoc BOl.l'AT'1'El<H O'LQlll C 0
~
~
L'p sa
TOP TRUNNION ASSEtlPLY The top trunnion assembly cons'sts of the top trunnion plate, the top trunnion, the welds and the body material immediately adjacent to the trunnion.. Figure 9 illustrates the elements of the assembly.
'a maximum due to seismic and torsional loads.
S (58)" =
(S (59) 2 ~
S (60) 2)
I Where S (59) 2 2
4
. 707 (. 50) ~D11 Fz 1.
Combined shear stress in the top trunnion" plate welds is
= Shear stress
.due to operator eccentricity.
S(60)
=
4 z+T8 ll+2 ll 3 (1. 4 1) mLl1 (D 1 1+ 2T11) 3
= Torsional shear due to operator eccentr'city and o erator "or ue.
P q
2.
Combined stress in base of trunnion body due to combined
- bending, torsion and seismic loads.
S (61)
(62)+S (63)
( (S (62)+S (63) ) 2
+
4 ( (S (64)+S (65) ) 2) ~
Where.
S (62)
=:Direct tensile stress, psi 7r (Dll - B2
)
= Bending tensile stress, psi Fz
+ W4gz 25m (D112 B22)
S (63) 32 ( (hix+FyK6)
+ (l4y+FxK6
)
Dll 55
1 OP 7f<UH I Ol /
fun'u" L
Doch/
5 l I I
~
~
~
~
56 t
'+ '~+
S(64)
= '" "V
25m (Dll 2
2 4
4(gx +gy B22)
= Direct shear stres
, psi r Torsional shear
- stress, psi 3.
Combined shear stress in top trunnion to shell weld is a
maximum due to seismic and torsional loads..
S (66)
=
(S (67)
+
S (68)
)
2 2
( 7)
(Mx+FyK6)
+
(M +FxK6
)
/
1 F>
. 707 (. 50) mDll2 mDllLll
= Shear stress due to operator eccentricity S (68)
=
< (Mz+Ts) (3Dll+2Tll) ll(Dll+2T
= Torsional shear due to operator eccentricity and operating torque.
57
i 0
A.
Introd>>ction To calculate
<<he natural frequency of the various components of the Triton NXL valve.,
a model system with a single degree of freedom is constructed.
The individual components and groups of components are modeled and analyzed as restoring spring forces which act to oppose the respective weight orces they. are subjected to.
The static deflection of teh component is calculated and is related to na<<ural frequency.as:
F
=
1 K
n 2a(
jj or or 2m hy The analysis details the equations and assumptions used in determining tne natural frequencies listed in the summary table.
S):etches are provided where appropriate.
B.'alve Body Assembly The body shell, as seen in Figure 1; is assumed
'to
~ experience loading clue to the entire valve weight.
.Natural Frequencv of teh body shell:
58
Frc<<ie>>c A,nalv.;i.;".
Nher e byl
=
1.3.
97 L 4U E
'j:5 Maximum deflection ofbody shell due to valve >Ieight, inches Figure 2 "hows. the banjo assembly in the body.
The natural frequency of the banjo a sembly is calculated using the following:
~)
F 9.8 H2 by where by2 3
N Bl 12EI 5'laximum deflection of sha t, inches
(
D. Cover Cap ~~.ssembl" As seen in Figure 6,
the cover cap supports the banjo.
'The natural frequency of the cover cap is calculated as Xollows:
where by>
9 A
3 by3 3 {m -1)
<<2 (. 5D(+
. 125) 2
~
2 1GrE T<
m 3
2
=. ~iaximum deflection of cover cap 59
ATTACHIIENT GENERAL ARRANG~ifEHT AND CROSS-SECTION DRU0ZNGS
0