United States Nuclear Regulatory Commission - Protecting People and the Environment

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 
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                                                            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
.
Page Last Reviewed/Updated Tuesday, November 12, 2013