United States Nuclear Regulatory Commission - Protecting People and the Environment

Bulletin 75-03: Incorrect Lower Disc Spring And Clearance Dimension in Series 8300 And 8302 ASCO Solenoid Valves



BL75003 

IE Bulletin No. 75-03                                        Date: 3/14/75 

INCORRECT LOWER DISC SPRING AND CLEARANCE DIMENSION IN SERIES 8300 AND 8302 
ASCO SOLENOID VALVES 

DESCRIPTION OF CIRCUMSTANCES: 

Recent abnormal occurrences have been reported at the Point Beach and 
Kewaunee  nuclear stations in which safety related valves manufactured by 
Automatic Switch Company (ASCO) failed to operate properly due to an 
incorrect lower disc spring and/or improper lever to lower disc stem 
clearance. Information contained in the reports submitted by NRC licensees 
and subsequent discussions between NRC and ASCO personnel have revealed the 
potential for similar failures with ASCO, 120 volt, 60 cycle solenoid valves
of the types listed below. 

          Series                             Form 

          8300-C                             F, U, RF or RU 
          8302-C                             F, U, RF or RU 

According to the manufacturer, valves of the types listed above should have 
a heavier duty spring on the upper than on the lower disc section. These 
springs are identified by a specific part number and color which may differ 
for each valve type. Incorrect lower disc springs as well as improper 
clearance between the lever and lower valve disc stem have been identified 
as the causes of recent valve failures. 

It has also been reported that incorrect valve disc springs have been 
included in repair kits supplied by the valve manufacturer. In case of 
uncertainty, licensees are advised to contact the ASCO valve service 
department regarding the proper disc springs and clearance for specific 
valve types. 

ACTION TO BE TAKEN BY LICENSEES: 

For all power reactor facilities' with operating license or construction 
permit: 

1.   Determine if ASCO valves of the types described above are in use or 
     planned for use in safety related systems. 
.

2.  Report to this office in writing, within 30 days for facilities with 
     operating license and within 60 days for facilities with construction 
     permit, the results of your findings with regard to Item 1. 

3.   If solenoid valves of the types described are in use or planned for use
     in safety related systems, include in your written reply the actions 
     you have taken, or plan to take, to prevent failures of the type 
     described above. Your written reply should also include the date when 
     such actions were, or will be, completed. 
     
Page Last Reviewed/Updated Tuesday, July 23, 2013