Patent ID: 8327874

Claim:
A high integrity protection system (HIPS) for testing the protection and pressure control of a piping system connected to a wellhead, the HIPS having an inlet connected to the wellhead and an outlet connected to the piping system, the protection system comprising: two sets of surface safety valves (SSVs) in fluid communication with the inlet, the two sets being in parallel fluid flow relation to each other, each set of SSVs including 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, either one or both of the two sets of SSVs operable as a flowpath for fluids entering the inlet and passing through the HIPS outlet to the common outlet pipe; two vent control valves (VCVs), each of which is connected to piping intermediate each of the two sets of SSVs, each of the VCVs being in fluid communication with a common vent line, whereby, upon opening of a VCV, process pressure between the two SSVs is vented; and a safety logic solver in communication with the SSVs and the VCVs, the safety logic solver generating signals to control the operation of the SSVs and VCVs; wherein during a full-stroke test, the safety logic solver is programmed to maintain one set of SSVs in an open position while moving the other set of SSVs from an open position to a closed position.