Information Notice No.80-11 – Generic Problems with ASCO Valves in Nuclear Applications Including Fire Protection Systems
SSINS No. 6870
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
March 14, 1980
Information Notice No. 80-11
GENERIC PROBLEMS WITH ASCO VALVES IN NUCLEAR APPLICATIONS INCLUDING FIRE
Description of Circumstances:
Enclosure 1 is a Recall Notice from The Viking Corporation, dated July 16,
1979 that identifies ASCO valves used in certain Viking fire protection
equipment that could fail.
Licensees should review their fire protection system components to determine
if the equipment identified in the Viking Recall Notice is in their
facility. If the identified equipment is installed in the fire protection
system, then the modifications specified in the Recall Notice should be made
and tested for proper operation. The requirements of the technical
specifications or any other licensee commitment should be complied with when
a fire protection system is disabled.
South Carolina Electric and Gas Company (Virgil C. Summer Nuclear Station)
reported to the NRC on October 24, 1979, a potential significant deficiency
regarding the effects of oil on elastomeric materials used in ASCO NP-1
solenoid valves. Specifically, these valves utilize an ethylene propylene
elastomer which expands or swells when brought into contact with oils,
possibly causing valve failure. For this reason, ASCO specifies these NP-1
solenoid valves for use in "oil free instrument air" systems.
Although instrument air systems are "oil free" by design, installation
instructions may specify the use of thread lubricants utilizing an oil base.
Thus, the potential exists for traces of this lubricant from threaded
connections in the air system, in addition to traces of oil from the air
compressors themselves, to come into contact with the elastomers in the
solenoid valves. Degraded elastomers can cause the solenoid valve to fail by
sticking, swelling closed flow paths, or rupturing causing leakage across
the seat or to atmosphere. Failure of the solenoid to function properly on
an active valve could prevent a system from performing its required safety
Some ASCO NP-1 solenoid valves are equipped with tags which state:
"Important this valve is equipped with ethylene propylene elastomers which
can be attacked by oils and greases. To be used for oil-free instrument
quality air. Clean pipe threads of cutting oils." Care should be taken to
use approved thread lubricants which do not contain oil for the installation
of these valves.
Information Notice No. 80-11 March 14, 1980
Page 2 of 2
ASCO offers viton elastomers as an option for their NP-1 solenoid valves.
The viton elastomers are not affected by oil or grease. Replacement kits of
viton elastomers are available for the NP-1 solenoid valves from ASCO. It is
recommended that ethylene propylene elastomers found in Class IE qualified
ASCO NP-1 solenoid valves be replaced with the viton kits.
In addition, enclosed is a letter from EG&G (Enclosure 2) dated December 26,
1979 that provides the results of an LER review of failure of solenoid
This Information Notice provided information about a potential safety
concern. No written response is required. If you desire additional
information regarding this matter, contact the Director of the appropriate
1. Viking Corporation Recall Notice
2. EG&G Letter, Dearien to Tiller
dated December 26, 1979
Page Last Reviewed/Updated Thursday, March 25, 2021