Process Engineering Division – Instrumentation and Automation Section – Daily Question – Question from 2020-10-20

Emergency shutdown, ESD emergency stop system

?ESD — Emergency Shutdown System. ESD is the abbreviation for Emergency Shutdown Device, and it has the following characteristics: (1) It reduces the probability of both control functions and safety functions failing simultaneously, ensuring that the safety protection system remains intact even in case of failures in the DCS components; (2) For large-scale installations or rotating mechanical equipment, the faster the response time of the emergency shutdown system, the better. This helps to protect the equipment and prevent accidents from escalating ； It also helps in distinguishing the records of accident causes. Since DCS processes a large amount of process monitoring information, its response speed is difficult to make fast ； (3) The DCS system is a process control system that is dynamic and requires frequent manual intervention, which may lead to human-induced errors ； ESD, on the other hand, is static and does not require human intervention; by setting it this way, human errors can be avoided.

A type of SIS system; an emergency shutdown system

ESD is an emergency shutdown system, while SIS is a safety instrumented system; ESD is part of SIS. The SIS consists of field instruments, logic processors, and actuators, all of which must be designed with safety in mind. A conventional ESD system is merely the logic processor part of the SIS, which, of course, also needs to be designed safely. Its characteristic remains PID control; thanks to its robust communication capabilities, it serves as a system for integrating all automated devices in a factory. SIS requires higher levels of reliability and availability compared to DCS, and standards such as IEC61508 and IEC61511 stipulate that SIS and DCS hardware should be installed separately. The DCS system is a process control system that is dynamic and requires frequent manual intervention, which may lead to human-induced errors ； Meanwhile, SIS (ESD) is static and does not require human intervention; this setup helps to avoid accidental actions by humans. It is usually used as a control scheme for complete sets of equipment, such as systems that form their own integrated systems for vacuum, wastewater, packaging, compressors, and so on. Their characteristic is that they require little analog control; they are extremely effective, convenient, reliable, and cost-effective for digital control. It is usually used as a sub-site of the DCS to facilitate monitoring. It is clear that from the diagram below, we can see that SIS includes ESD, ITCC, etc., while under DCS are PLC, FCS, etc.

ESD is the abbreviation for Emergency Shutdown Device; in Chinese, it is referred to as an emergency shutdown system. It operates independently of the DCS system and also has a higher safety level than the DCS system.

ESD is the abbreviation for Emergency Shutdown Device, which refers to the emergency shutdown system

ESD is the abbreviation for Emergency Shutdown Device, which refers to a system for emergency shutdown. It has a high level of safety and constitutes a safety protection device for factory operations

The ESD system is an emergency shutdown system that was developed in the 1990s, and it has received consistent praise for its high reliability and flexibility.

ESD – Emergency Shutdown System. ESD is the abbreviation for Emergency Shutdown Device, and it has the following characteristics: (1) It reduces the probability of both control functions and safety functions failing simultaneously, so that a malfunction in the DCS does not put the safety protection system at risk; (2) For large-scale installations or rotating mechanical equipment, the faster the response time of the emergency shutdown system, the better. This helps to protect the equipment and prevent accidents from escalating ； It also helps in distinguishing the records of accident causes. Since DCS processes a large amount of process monitoring information, its response speed is difficult to make fast ； (3) The DCS system is a process control system that is dynamic and requires frequent manual intervention, which may lead to human-induced errors ； ESD, on the other hand, is static and does not require human intervention; by setting it this way, human errors can be avoided.