Some consideration on how often safety critical valves should be tested based on expected utility theory

Abstract

The regulation given by the Petroleum Safety Authority Norway (PSAN) requires annual testing of safety critical valves. In the present paper we discuss the rationale for this requirement, as annual testing by the operators is considered as too strict. The expected utility theory which is the backbone for all economic thinking is used as basis for the discussion. We show that requirements formulated by the authorities on how often safety critical valves should be tested, usually will be stricter than what the operators prefer. We also show that the requirement on annual testing likely will be too strict also from a societal point of view, if the effects of annual testing are seen only as improvements in reliability of the valves. One is then disregarding the fact that testing of safety critical valves also has negative effects on safety for those who perform the tests, as well as negative effects for the environment.