The O&M Code was developed when it was decided to move Pump and Valve In-Service Testing Requirements from ASME Boiler and Pressure Vessel Code Section XI to a standalone Code. IST for Pumps was originally is ASME Section XI IWP and for Valves IWV. Safety and Relief Valves were a Power Test Code and not in the scope of the ASME Boiler and Pressure Vessel Code. IWP and IWV were developed after plants had been designed and built. The desire was that no back-fits were to be required to comply with IST requirements. After the 1986 Edition, IWP and IWV requirements were moved into O&M. Appendix 1 of OM was what used to be the Power Test Code.
While this was going on, the NRC issued what has been called “the Richardson Letter”. Among other things, that letter required that IST for pumps better asses the condition of the pumps by putting higher accuracy instrumentation on the test pipe. For many plants, this was the minimum recirculation pipe. Over the course of time, the committee was able to get agreement that if a centrifugal pump were tested “back on its curve” increased instrument accuracy would be meaningless. This was the genesis of what we now call comprehensive Pump testing. Additionally, there were several alternative methods for valve testing that had been developed. It became clear, that simple periodic stroke timing of a power operated valve was simply not adequate for detecting degrading performance.
This presentation will discuss how Pump and Valve In Service Testing evolved to what it is today and discuss what might be alternatives in the future.
I want to thank Robert Parry, who provided some insights into this presentation specifically where my memory needed a bit of jogging.
Paper published with permission.
