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ACCESSION #: 9508170275 KEYSTONE 3950 Greenbriar, Stafford, Texas 77477 Anderson, Greenwood & Co. August 10, 1995 VIA FAX TO NRC OPERATIONS CENTER (301) 816-5151 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Ref: Our July 14, 1995 10CFR21 Noncompliance Report Gentlemen: The purpose of this correspondence is to provide results of testing performed to evaluate the problem reported in our July 14, 1995, letter. Testing was performed to establish the amount of deviation from nameplate set pressure that could result from testing AGCO's 81P using air as the test media instead of water. Valves were assembled and set pressure adjustments were made following the factory procedure using water as the test media. The valves were then checked using air as the test media. If the air test method did not result in the same set pressure value, further adjustments were made to satisfy the air method criteria. For valves where adjustments were necessary, the factory water method was repeated and the resulting set pressure recorded. The difference between the first water test setting and the second water test reading represents the potential deviation from nameplate set that could result from adjusting the valve using the air method. Two series of tests were performed. One using KEL-F seat material and another using PEEK seat material. Set pressures ranging from 100 psi to 2000 psi were tested. Results of the tests indicated the following: Potential Set Set Pressure Range Pressure Deviation Valve/Seat Material (psig) Above Nameplate (%) 81P/KEL-F 100-750 4-15 81P/KEL-F >750 None 81P/PEEK 100-750 20-40 81P/PEEK >750 None Since the air test method is based on the valve's first leakage on increasing pressure, results are very dependent on the effectiveness of the valve seat. PEEK is a very hard plastic relative to P.O. Box 944, Phone: (713) 274-4400, Stafford, Texas 77497-0944 Telex: 0775219, Fax: (713) 240-1800 Document Control Desk U.S. Nuclear Regulatory Commission August 10, 1995 Page 2 KEL-F and requires more seating load to effect a seal. Therefore the potential deviation for PEEK is greater than for KEL-F. For both materials, the higher set pressures (>750 psi) showed no deviation between water and air test methods. For the lower set pressures, the range of deviations observed in our tests showed no significant trend. The deviations shown in the above table are only applicable to AGCO's Model 81P liquid relief valve that has had its set pressure adjusted after shipment from the factory using air as the test media and first crack (leak) at 95% of set pressure as the criteria. Any valve that has AGCO's factory lead seal unbroken or has been adjusted using the water test method is unaffected. For set pressures below 750 psi, the 81P should only be set pressure adjusted using the water test method described in Procedure N05.9040.180, Revision F. For set pressures above 750 psi, either the water or air test method may be used. We are in the process of preparing letters to all customers who have purchased this model explaining the above findings and recommended procedures. Please do not hesitate to contact me if you have any questions. Very truly yours, ANDERSON, GREENWOOD & CO. J. Alan West, P.E. Vice President, Engineering JAW:mnp Atta. c: Mr. Greg Hyland Mr. Juan Gomez Mr. Ed Ross Mr. Doug Snyder Mr. Steve Stansbury Mr. Jim Baca NRC08.095 *** END OF DOCUMENT ***