ML20236N483
| ML20236N483 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 07/23/1987 |
| From: | Fisher R PAUL-MUNROE HYDRAULICS, INC. |
| To: | Taylor J NRC |
| References | |
| REF-PT21-87, REF-PT21-87-123-000 0377E, 377E, PT21-87-123, PT21-87-123-000, NUDOCS 8708110517 | |
| Download: ML20236N483 (11) | |
Text
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Mail to P O. Box 5900 Orange, CA 92667 Energy Products "o"*89ffa"a Tei.wn., j'[*$
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'ph 23 July 1987 Mr. James Taylcr Director of the Office of Inspection and Enf orcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 W
Subject:
Fine.1 report:
Potential 10CFR21 report regarding pressure swithces.
Reference:
- 1. Paul-Munroe Potential 10CFR21 report dated 15 April 1987.
- 2. NRC report Number 99900337/87-01.
- 3. Failure analysis report on Pressure Switches. Attached.
- 4. Failure analysis report on Linear Position Tranducer, q
Attached.
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- 5. Failure analysis report on Servo Amplifiers.
Attached.
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Dear Mr. Taylor:
This letter is to finalize the subject 10CFR21 investigation of the failure of six ITT Neo-Dyn pressure switches used in the assembly of Valve Operator systems manufactured by Paul-Munroe and installed in Houston Lighting and Power Company's South Texas Projects 1 and 2.
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The valve operators had been in storage for two years prior to installation.
Reports and observations from the site indicated that the protective covers had been removed from the operators and that they were dusty, dirty, rusting, and had water dripping on them.
Samples of the hydraulic fluid for analysis were not made available to Paul-Munroe however, under these conditions, it is certain that the fluid would have become heavily contaminated.
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COMPONENTS e
SYSTEMS INSTALLATION SERVICE MANUFACTURING
Mr. James Taylor Director of the Office of Inspection and Enforcement 23 July 1987
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Page Two Reference 3 is the failure analysis report prepared by ITT Neo-Dyn subsequent to their analytical study of three pressure switches returned to Paul-Munroe l
from the valve operator systems at South Texas.
This report concludes that l
metallic particles from the hydraulic fluid were embedded in the sealing diaphragm resulting in punctures of the diaphragm in all three units under examination.
A sketch of the inlet port section of the pressure switch showing the sealing diaphragm and the actuating piston clarifies the failure l
mode.
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It.is important to note that each valve. operator is equipped with three pressure switches: two sensing hydraulic fluid pressure and one sensing nitrogen pressure.
All pressure switch failures (six reported) were switches connected to the hydraulic fluid side of the systems.
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6 MUL-A1UNROE
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Mr. James Taylor Director of the Office of Inspection and Enforcement 23 July 1987 Page Three In addition to the pressure switches, Paul-Munroe received two linear potentiometers and two servo amplifiers from the South Texas site for evaluation (Reference 4 and 5).
The failures o.
these components are also attributed to poor storage conditions and improper maintenance and handling.
Failures of solenoid operated control valves were also reported.
Valves were not returned to Paul-Munroe for evaluation however, fluid contamination is the primary cause of failure of these hydraulic components.
It is the conclusion of this report that fluid contamination, lack of recommended maintenance while in storage and improper handling of the valve operators was the direct cause of the indicated component failures.
Paul-Munroe's client, Control Components Incorporated (CCI), arranged to have all the valve operators in question returned to our factory for the recommended five year refurbishment.
This has been accomplished for the Unit 1 operators and they have been returned to the site for reinstallation.
The Unit 2 operators have also been returned to Paul-Munroe for refurbishment and we expect to perform this work soon.
To prevent reoccurrence of component failures of this nature, Paul-Munroe has recommended to CCI and to Bechtel Power Corporation that the preventive maintenance procedures addressed in the Installation, Operation, and Maintenance Manual provided by Paul-Munroe be routinely practiced.
These procedures include periodic monitoring of the cleanliness of the hydraulic fluid.
Respectfully submitted, PAUL-MUNROE ENERGY PRODUCTS 1h Richard C. Fisher Director of Engineering
Enclosures:
RCF:ked 0377E
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13 May 1987 Mr. Ed Villalva Control Components Inc.
22591 Avenida Empresa Rancho Santa Margarita, CA 92688 Sub. ject:
Repair Report for Servo-Amplifier Boards.
Reference:
Control Components Inc. Purchase Order Number 71258
Dear Mr. Villaiva:
Attached please find the servo-amplifier repair report prepared by California G & K Design Inc. on Paul-Munroe Part No. PD88085-2028.
The probable cause of failure is a blown fuse resulting from technician error.
Also note that the circuit boards were corroded, dirty and greasy.
PAUL-MUNROE INCORPORATED Energy Products Division ff b Ad R.C. Fisher Director of Engineering
Enclosure:
RCF:ked 0277E SERVICE SYSTEMS INSTALLATION COMPONENTS MANUFACTURitwG
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May'1,,1987-cditar=1. caro issime.
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- Paul-Munroc 2807 Oregon Court, Unit D4 Energy Products D1yision Torrarre, California 90503 (213) 618e66 1734 W. Sequoia Ave.
Orange, CA. 92668 Repair report - PO E31066 PD 88085-202B Servo Arnp S/N F5003 and S/N FS00,5 Clean corrosion dirt and grease. Replaced blown fuse, Re-test per PA - 88079 Kenneth H. Ball gy California G & K Design, Inc.
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15 May 1987 Mr. Ed Villaiva Control Componente Inc.
22591 Avenida Empresa Rancho Santa Margarita, CA 92688
Subject:
Analysis for Bourns Long Travel H naar Position Transducer
Reference:
Control Components Inc.
Purchase Order No. 71258, Item 2
Dear Mr. Villaiva:
Attached please find a description of the anomolies observed for the Bourns Long Travel Linear Position Transducer (potentiometer) designated as Bourns Part Number 2051945302 (Paul-Munroe Part Number PA89292-01).
Both visual examination and electrical tests were used to determine the condition of the potentiometers.
In
- summary, the electrical tests indicated that the potentiometers would have performed their intended function.
Mechanic 111y, the pnis, were damaged due to improper storage, handling and maintenance.
PAUL-MUNROE INCORPORATED Ener Products Division r#
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i Richard C. Fisher Director of Engineering RCF:ked 0281E
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SERTOE MANUFACTURING SYSTEMS INSTALLATION COMPONENTS
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I The potentiometers were visually. examined immediately upon receipt from the i
job site.
Two of the potentiometers had bent shafts.
One shaf t was bmt where the threaded section makes the transition to the unthreased section.
The other shaft was bent at approximately 7.5 inches from the threaded end.
Evidence of the shaft rubbing against the tube cover was also observed.
Electrical tests were performed and two non-conformances were noted.
The
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potentiometers demonstrated excessive contact resistance variation which is 1
comonly referred to as " dead spots" and the insulation resistance was significantly lower than the original factory acceptance criteria.
After the electrical tests were completed the units were disassembled and the lubricant was found to be dried-up. -The location of the dried lubricant was such that it interfered with the wiper making full contact with the conductive element:
as observed by contact. resistance variation test.
Based on the above findings the observed anomolies can be attributed to the bent shafts and the dried lubricant resulting from improper storage, handling and maintenance.
0282E
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1 l Aerospace Controls Division 1E
. PO Ba 3789, Chatswodh, CA 01313-3789 21411 Prairie Street, Chatsworth, CA 91311-5888 Neo-Dyn Facility e
(018)998-8611
.9 Apr 87 uTo:
Paul-Munroe Hydraulics
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L$.Am er, 1701 West Sequoia Ave.
Q. A. Manager Orange,.CA-92668
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L. Sunham Attention:
Richard C.
Fisher
'S, Nanda' J. Dregne
Subject:
Failure Analysis Report, 1 Apr 87:
D. Griffith I '. 0 SCOPE This analysis.was conducted'to. identify the'cause of leakage on
.three (3) Neo-Dyn Pressure Switches, Model.No. 100P1S780 (Paul-Munroe PA88542-01).
Installed on Paul-Munroe Hydraulics.
Inc. valve operator assembly.- It is of. interest to note that the gas' pressure switch of the same part number installed.in the
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system did not show signs of leakage, nor did a set of switches from a second system.
The analysis of. Para's. 2.0 thru 2.6 were conducted in the-presence of:
Mr.-Richard C.
Fisher, Paul-Munroe, Director of Engineering Mr. Kamalakar R.
- Naidu, N.R.C.,
Reactor Inspector-
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Mr. Larry Dunham, Neo-Dyn, Engineering Manager
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-Mr. Jon Dregne, Neo-Dyn, Regional Sales Manager Mr. Satish Nanda, Aerospace Div., Director of Quality Mr..Lanny Amper, Neo-Dyn, Quality Assurance Manager Mr. Phil Davies, Neo-Dyn, Engineering Technician o
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SWITCH IDENTIFICATION PRESSURE SETTING ASSy DATE Unit'No.
1~ Tag No. AIMS-PSH-7411 Incr. 1950 1 50 psi 8409 (Sept., 1984) l Unit No. 2 Tag No. AIMS-PSL-7411 Decr. 1500 1 25 psi 8409 (Sept., 1984)
Unit No. 3 Tag No. CIMS-PSL-7431 Decr. 1500 1 25 psi 8409 (Sept., 1984) 4 I
- FORMPb4A
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Aerospace Controls Division 1 P.O. Box 3789, Chatsworth, CA 91313-3789 l
21411 Prairie Street, Chatsworth, CA 91311-5888 Neo-Dyn Facility gg33) 993 333 3 Page 2 l
2.0.
ANALYSIS SEQUENCE:
1' l
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2,i VISUAL EXAMINATION
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External appearance of the units appeared normal.
Removed cover assembly.
l Fluid was observed around the actuator shaft and adjustment nut.
~ 2. 2 PROOF TEST - Test media - Air pressure Unit No. 1 Visual leak was observed at 900 psi.
Unit No. 2 Visual leak was observed at 800 psi.
Unit No. 3 Visual leak was observed at 300 psi.
2.3 FUNCTIONAL TEST - Actuation /Deactuation-Unit No. 1 Unable to reach actuation pressure, major leakage at 1400 psi.
Unit No. 2 Actuation at approximately-7 psi.
Deactuation at approximately 1400 psi.
Unit No. 3 Actuation at approximately 1650 psi, major leak occurred, unable to verify deactuation setting.
2.4 DISASSEMBLY Removed port caps, visually examined diaphragms, pressure plate and body.
Unit No. I Metallic piece of material was found piercing through the diaphragms at the toroid area causing a hole.
Unit No. 2 One area of the toroid showed some impressions or tearing, no foreign material was found.
Unit No. 3 2 pieces of foreign (black) material was found on the diaphragm, one piece located in the center of the diaphragm which did not appear to cause a puncture.
The second piece was located in the toroid area.
This area appeared to be torn or fractured.
f OHM 2f4A
P.O Box 3789, Chatsworth, CA 91313-3789 Aerospace Controls Division
,,,,, erairie street, Chatsworth, CA 91311-5888 Neo-Dyn Facility (818)998-8611 Page 3 2.5 MECHANICAL MOVEMENT CHECK Unit No. 3 Mechaniurl movement of the pressure plate measured
.011 inch (within specification).
2.6 RE-ASSEMBLE UNITS The three switches were re-assembled using new diaphragms and air proofed at 5000 psi.
No leakage occurred.
2.6.1 PRESSURE TEST All three units were precsure tested at 3000 psi for 10 minutes.
No leakage occurred.
j 2.6.2 FUNCTIONAL TEST - Actuation /Deactuation All three units functioned within the required set points.
Unit No. 1 Actuation at 1940 psi, Deactuation at 1820 psi.
Unit No. 2 Actuation at 1030 psi, Deactuation at 1520 psi.
Unit No. 3 Actuation at 1620 psi, Deactuation at 1540 psi.
4 2.7 24 HR. PROOF TEST @ 5000 PSI
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Test media - Sjlicone oil.
Unit No. 2 was proof tested at 5000 psi for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
No leakage occurred.
Disassembled and examined diaphragm for damage.
No damage observed.
2.8 VISUAL ANp DIMENSIONAL EXAMINATION UNITS 1,
2, AND 3 Pressure Plate 064-0010-04, all dimensions and finishes found in tolerance.
j Body 017-0040-04, all dimensions and finishes found in tolerance.
F OHM 264A
' Aerospace Controls Division 1 P.O. Box 3789, Chatsworth, CA 01313-3789 21411 Prairie Street, Chatsworth, CA 91311-5888 1
' Neo-Dyn Facihty (818)998-8611 Page d' l
l 3.0 CHEMICAL' ANALYSIS OF CONTAMINATION i
3.1 Metallic particle embedded in the diaphragm of Unit #1 had entered the diaphragm from the inlet direction (port. cap side).
Unfortunately, during the cleaning of the oil on the diaphragm, the metallic particle was dislodged and lost.
3.2 The EDX spectra obtained from the contaminants from Unit #3 showed major peaks for Silicon, Carbon, Aluminum and Oxygen, and minor to trace peaks for Iron, Potassium and Calcium.
4.0 CONCLUSION
The cause of the failure was due to fluid contamination in the valve operator assembly, resulting in punctures of the sealing diaphragm of all three units.
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I FORM 2t.4A