The function of the interlock system ESD

ESD is short for Emergency Shutdown Device; in Chinese, it refers to the emergency shutdown control system, which can also be called the safety instrumented system. When the conditions meet the set parking data requirements, the system initiates an automatic emergency stop. It can not only respond to the dangers arising from the production process exceeding safety limits, but also detect and handle its own faults, thereby keeping the production process in a safe state according to predetermined conditions or procedures, in order to ensure the safety of personnel, equipment, and the environment surrounding the factory.

The emergency shutdown system operates at a higher control level than the DCS; in case of an emergency, it enables one-button shutdown of the entire plant.

ESD — Emergency Shutdown System. ESD is the abbreviation for Emergency Shutdown Device, which refers to the emergency shutdown system. This specialized security protection system was developed in the 1990s and has received consistent praise for its high reliability and flexibility. The ESD emergency shutdown system, in accordance with the principle of safety independence, operates independently of the DCS distributed control system, and its safety level is higher than that of the DCS. Under normal conditions, the ESD system remains in a static state and does not require human intervention. As a safety protection system, it operates above the production process control to monitor the safety of the devices in real time. Only in the event of an emergency in the production equipment is it not necessary to go through the DCS system; instead, the ESD directly sends out protection interlock signals to safeguard the on-site equipment and prevent the spread of danger from causing significant losses. According to available data, people’s judgment and actions in dangerous situations are often delayed and unreliable; when operators are faced with a life-threatening situation, they must react within 60 seconds, and the probability of making a wrong decision is as high as 99.9%. Therefore, it is highly necessary to install safety interlocks that are independent of the control system; this is an important principle for ensuring safe production. It moves when it should move, and remains still when it shouldn’t – this is a notable feature of the ESD system. Why is an independent ESD system necessary? Of course, general safety interlock protection functions can also be implemented by a DCS. However, for larger-scale emergency shutdown systems, they should be installed separately from the DCS in accordance with the principle of safety and independence. There are several main reasons for this: (1) to reduce the probability of both control functions and safety functions failing simultaneously, so that a malfunction in the DCS does not compromise the safety protection system; (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 identifying the causes of accidents and keeping records of them. DCS processes a large amount of process monitoring information, so 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.

ESD is the abbreviation for Emergency Shutdown Device, which refers to the emergency shutdown system. In accordance with the principle of safety independence, it operates independently of the DCS distributed control system, and its safety level is higher than that of the DCS. Under normal conditions, the ESD system remains in a static state and does not require human intervention. As a safety protection system, it operates above the production process control to monitor the safety of the devices in real time. Only in the event of an emergency in the production equipment is it not necessary to go through the DCS system; instead, the ESD directly sends out protection interlock signals to safeguard the on-site equipment and prevent the spread of danger from causing significant losses.

The Emergency Shutdown system, EDS, also known as the Safety Interlocking System, SIS, is designed to respond to and protect against potential hazards in petroleum refining and chemical processing plants as well as large-scale industrial units, preventing situations from worsening if no action is taken; it enables these plants and units to cease operating under specified conditions or procedures. This reduces the likelihood of severe accidents occurring in the equipment, minimizes unplanned shutdowns, and prevents incidents that result in serious injuries to people or significant damage to equipment. Therefore, it is necessary to install emergency shutdown interlock systems in petroleum refining and chemical production plants as well as large-scale units, as they play an important role in ensuring the safe operation of these facilities.