ML20133G974

Part 21 Rept Re Anchor/Darling Valve Co Swing Check Valves W/Loose Set Screws &/Or Missing Lock Welds,Reported by Palo Verde Nuclear Generating Station.All Customers W/Similar Valves Notified.Ltr Re Waterford 3 Valves Encl

ML20133G974
Person / Time
Site:	Palo Verde, Waterford, 05000000
Issue date:	07/31/1985
From:	Knieser G ANCHOR/DARLING VALVE CO.
To:	Courtland P NRC
References
REF-PT21-85, REF-PT21-85-352-000 PT21-85-352, PT21-85-352-000, NUDOCS 8508090142
Download: ML20133G974 (4)

Text

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s+ m 55 car Anchor / Darling 52 i Valve Company 701 FIRST STREET P.O. BOX 3428 WILLIAMSPORT, PA 17701-0428 l

(717) 327-4800 TELEX: 759953 July 31,1985 Nuclear Regulatory Commission Mail Drop EWW 359 Washington, D.C. 20555 Attn: Paul Courtland

Subject:

Swing Check Valve Problem Reported by Palo Verde Nuclear Generating Station Gentl emen:

Anchor / Darling has notified all customers with valves similar to those reported by the Palo Verde Generating Station as having loose set screws and/or missing lock welds of the potential problem. A copy of one of the letters is enclosed for your information.

Please call me if you have any questions or need additional information.

Very truly yours, ANCHOR / DARLING VALVE COMPANY sb '

G. W. Knieser Q. A. Manager GWK:dz Enclosure os N k B508090142 B50731 2 ADOCK 050 gDR

Anchor / Darling Wlve Company 701 FIRsT STREET i P.O. BOX 3428 l I

WLLIAMSPORT. PA 17701-o428 (717) 327-4800 TELEX: 759953 July 25,1985 LOUISIANA POWER & LIGHT COMPANY Ebasco Services, Inc., Agent g#C i

Waterford SES Unit 3 Ef DD P.O. Box 70 Killona, LA 70066 ju[ g.%

Subject:

Ebasco P.O.'s NY-403458 057 NY-403461 Waterford SES Unit 3 A/DV S.O.'s E-6373, E-1273 4463 and 4474 Gentlemen:

During installation of Anchor / Darling swing check valves at the Palo Verde Nuclear Generating Station, it was discovered that lock welds were missing on several valves.

Most 150 lb. and 300 lb. pressure class Anchor / Darling swing check valves utilize a set screw in the hinge support for the purpose of keeping the hinge pin from rotating. On some designs, this set screw also prevents the hinge pin from sliding cut of the hinge support. The set screw is required to be lock welded to prevent it from backing out in service. The absence of this lock weld is a safety concern since the set screw could conceivably back out in service allowing the hinge pin to slide out of the hinge support thus causing a loss of valve operability.

In a related problem at Palo Verde, the disc nut pin on several check valves was not lock welded as shown on the valve assembly drawing. This lock weld is necessary to retain the disc nut pin which prevents the disc nut frcm backing off the disc and rendering the valve inoperable. As an alternate to the lock weld, Anchor / Darling currently recomends peening the pin to hold it in place as detailed on the attached sketch.

A review of our records indicates that you may have 150 lb. and 300 lb. pressure class Anchor / Darling check valves similar to the valves at Palo Verde installed in your plant. In view of the foregoing, we recommend that you inspect these valves at your earliest opportunity and verify that the hinge pin set screws have been lock welded and that the disc nuts are retained as shown on the valve assembly drawing or as outlined on the attached sketch.

Continued . . . .

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. LOUISIANA POWER & LIGHT COMPANY Page Two Ebasco Services, Inc., Agent July 25,1985 Should you find this condition, or if you have any questions or require additional information, please contact John Chappell at (717) 327-4856 or Bill Knecht at (717) 327-4811.

Very truly yours, J

ANCHOR / DARLING VALVE COMPANY H. L. Patterson Manager. : Contract Administration

/e1 Encl.

- cc: J. J. Chappell G. W. Conlan W. G. Knecht

G. W. Knierer R. H. Luhta E. V. Tice S.O. Files (5) 1 t

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Type 304 or 316

. Stainless Steel Pin Peened at Both Ends 9

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1. Nominal Pin Diameter = Nominal Hole Diameter

= 1/8 in. minimum

2. Initial Pin Length should be 1/8 in, to 1/4 in. longer.than the Nut Flat to Flat Dimension.'

l J.J.C. 6/8/83 l

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