Extrinsic Safety Systems

Abstract

Everything dies, breaks, or runs out of gas. Everything. This is especially true for extrinsic safety systems. In contrast to intrinsic safety in which the process is designed to be inherently safe (1), extrinsic safety involves the addition of devices, which must perform some action in order to mitigate process risk. These devices may be passive devices such as pressure relief valves or active devices such as safety instrumented systems (SIS). Whether active or passive, the devices still must perform some action in order to mitigate risk. How well the devices perform the action determines whether the incident is successfully mitigated or a hazardous event occurs.