Patent ID: 8725434
Filing Date: 2014-05-13
Classification: E21B,F16K,Y10T

Abstract:
1. A method of testing a high integrity protection system (HIPS) with a predetermined pressure trip setpoint, the method comprising: providing a high integrity protection system (HIPS) that has first and second sets of surface safety valves (SSVs) in fluid communication with an inlet from an upstream pipeline, the two sets being in parallel with each other, each set of SSVs having two SSVs in series, the outlet of the second set of SSVs being connected to the outlet of the first set of SSVs such that the outputs of both sets of SSVs proceed through a common outlet pipe to a downstream piping system, the SSVs being operable in response to signals from a safety logic solver; and providing a safety logic solver to: initiate a manual full shutdown of the HIPS during normal operations; record pressure versus time data of fluid flow from the upstream pipeline upstream of the HIPS inlet and from the downstream piping system downstream of the HIPS outlet; and upon the closing of the SSVs, determine whether the recorded upstream pressure reached a predetermined maximum allowable piping pressure (MAPP) of the downstream piping system, in which case; determine an elapsed process safety time (PST) between the initiation of the manual full shutdown and the time at which the upstream pressure reached the MAPP; determine if the SSVs required more than half of the PST to stroke from fully opened to fully closed, in which case signaling an alarm to operators; and determine if the recorded downstream pressure reached the MAPP, in which case lowering the HIPS pressure trip setpoint.