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Information Notice No. 83-57: Potential Misassembly Problem with Automatic Switch Company (ASCO) Solenoid Valve Model NP 8316
SSINS No.: 6835 IN 83-57 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 August 31, 1983 Information Notice No. 83-57: POTENTIAL MISASSEMBLY PROBLEM WITH AUTOMATIC SWITCH COMPANY (ASCO) SOLENOID VALVE MODEL NP 8316 Addressees: All nuclear power reactor facilities holding an operating license (OL) or construction permit (CP). Purpose: This information notice is issued to alert licensees to a potential problem with ASCO three-way solenoid-operated pilot valves, type NP-8316 in 3/8" and 1/2" NPT sizes. Should a 1978 version of the manufacturer's installation instruction bulletin be followed, certain parts of the subject solenoid valves would be incorrectly assembled. Such misassembly can lead to air leakage past the valve seat of the affected valve, although the valve would still operate. No specific action or response is required at this time. Description of Circumstances: Franklin Research Center (FRC) in Philadelphia, Pennsylvania is under contract to the NRC to perform an independent testing and analysis program pertaining to ASCO solenoid valves. During the analysis phase, FRC noticed that the original ASCO Installation and Maintenance Instruction (Form V-5967) for Bulletin NP-8316 valves pictured the pressure and exhaust diaphragm assemblies backwards. The diaphragm assemblies should be positioned so that the large metal washer faces the bonnet and the small washer faces the body; this seats the surface of the diaphragm against the valve body (see attached diagram). ASCO informed the NRC that NP-8316 valves were always assembled correctly in the factory and most maintenance personnel will install new diaphragms as they were installed before and not in accordance with the picture in Form V-5967. ASCO has also indicated that despite the FRC report, no problems of this nature have been reported in the field. The ASCO Installation and Maintenance Instructions, Form V-5967, was issued in 1978 and superseded by revised Form No. V-5967R1, published in 1981. The latter shows the correct orientation of both diaphragms. It is possible that during these three years some maintenance crews used the picture on the original ASCO Form V-5967 instructions for maintenance, installing the diaphragms backwards instead of replacing them in the same orientation as they had been removed. 8308040043 . IN 83-57 August 31, 1983 Page 2 of 2 ASCO assured the NRC that valves with the diaphragms installed backwards will still operate, but that the valves would leak. Therefore, this error may go unnoticed, if the valves were not operated be being returned to service. These valves are used extensively in safety-related systems at both BWR and PWR nuclear power plants. Although no written response to this notice is required, it is suggested that holders of OLs or CPs review this information notice for applicability at their facilities. If you have any questions regarding this matter, please contact the Regional Administrator of the appropriate NRC Regional Office, or this office. Edward L. Jordan Director Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement Technical Contact: W. Laudan, IE (301) 492-9759 Attachments: 1. Valve Diagram 2. List of Recently Issued IE Information Notices .
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