United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9907220113


Curtiss-Wright Flow Control Corporation
Solutions for Today ... Standards of Tomorrow
2950 Birch Street, Brea, CA 92821-6235
(714) 528-2301
FAX (714) 528-0128

July 14, 1999

Document Control Clerk

Subject: Notification of a potential equipment failure of ITT Pressure Switch Model 132P5S

As a courtesy and obligation to Global Nuclear Power Safety the following data is provided for information only. Enertech recently procured the above referenced model pressure switch from ITT Neo-Dyn division. The switches were incorporated into electro-hydraulic valve actuator equipment in both a safety related and commercial application. While in a testing mode and prior to shipment and installation into a Nuclear Power Plant, the reliability of the switch was questioned after multiple test failures. The failures occurred to non safety related application switches, however the model numbers are identical to a safety related pressure switch installed on the same equipment.

All switches were returned to ITT for root cause evaluation. ITT determined the 132P "Modular Design" model pressure switch may not provide electrical signal once mechanical activation has occurred from a 44 synchronization process". ITT performed design evaluation and functional testing to ascertain the root cause of the failures. ITT determined the 132P model switch exhibited movement of the electrical component when vibrated or cycled due to the mechanical set screw design. This results in the electrical component no longer functioning. The corrective action determined by ITT was to rebuild the switches, by reverting to a past design configuration, and re-testing to their internal ATP. The current "Modular Design" has been in existence for approximately (1) one year with no adverse problems. This product is manufactured and supplied as a Commercial Grade Item. Approximately 900 units a month are manufactured, some potentially being provided to other Nuclear Industry OEM's through ITT's distributor network.

Enertech has no installed base of this model pressure switch. The recent reliability testing of the traditional designed and manufactured switch demonstrated that the problem will be eliminated with implementing the aforementioned corrective action.


James L. Leachman

Doc #: Q:\everyone\NRC99001.DOC


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