Partial stroke testing

Partial Stroke Testing (PST) is a functional safety technique primarily used in process industries to test and validate the performance of safety critical systems, particularly those involving safety valves and actuators. The purpose of PST is to verify that the safety system is capable of performing its intended function without conducting a full stroke test that would disrupt process operations. In a typical PST, the actuator of a safety valve is moved only partially (not completely) to check its mechanical and operational integrity.