What is an Emergency Shutdown (ESD) system?

An Emergency Shutdown System (ESD) is a type of SIS that detects hazardous conditions and automatically shuts down part or all of a process to prevent or minimize damage. ESD systems respond to abnormal conditions (high pressure, high temperature, fire detection, gas leak) by closing isolation valves, stopping pumps and compressors, and de-energizing equipment. ESD systems are independent from the BPCS, use dedicated sensors and final elements where possible, and are designed to meet specific SIL requirements. Levels include unit shutdown, area shutdown, and plant-wide shutdown.