ESD

An automatic protection system which will act to shut down the plant if it enters a potentially dangerous state. In some countries this is called a Safety Instrumented System (SIS).

An emergency shutdown system for a process control system includes an emergency shutdown (ESD) valve and an associated valve actuator. An emergency shutdown (ESD) controller provides output signals to the ESD valve in the event of a failure in the process control system.

An Emergency Shutdown (ESD) system prevents or minimizes the consequences of emergency situations, helping to avoid loss of human life, damage to the environment, and/or loss of equipment.

The ESD system is distinguished from other facility safety systems in that it responds to a hazard situation which may affect the overall safety of the entire facility. Without an ESD system, an incident at a hydrocarbon facility may be provided with "unlimited" fuel supplies that can destroy the entire plant. if the reliability of an ESD system is very poor the facility might be considered without adequate protection.