Emergency Shut Down Systems (ESD) are specialized highly reliable control systems for high risk industries like Oil and Gas, Nuclear Power or other Environments with explosion risk (Ex.). Their purpose is to protect personnel, plant, and the environment in case the process goes beyond the control margins.
Actions of Emergency Shutdown System
- Shut down of part systems and equipment
- Isolate hydrocarbon inventories
- Isolate electrical equipment *)
- Prevent escalation of events
- Stop hydrocarbon flow
- Depressurise / Blowdown
- Emergency ventilation control *)
- Close watertight doors and fire doors *)
Traditionally risk analyses has concluded that the Emergency ShutDown system is in need of a high Safety Integrity Level, typically SIL 2 or 3.
Basically the system consist of field-mounted sensors, valves and trip relays, system logic for processing of incoming signals, alarm and HMI units.
The system is able to process input signals and activating outputs in accordance with the Cause & Effect charts defined for the installation.