Design issues of blowdown valves

1. Is the correct translation a pressure relief valve? 2. What are the differences from ordinary pneumatic on-off valves in terms of type, valve material, air circuit design, etc.? 3. What are the requirements for solenoid valves? SIL? 4. Are there any requirements regarding travel time? 1. It usually refers to a discharge valve for liquids, used to remove material from a container/reactor. For example, discharging the hydrocarbon materials at the bottom of the tower under fire conditions. 2. No. But note that in the case of fire scenarios, engineering regulations may require fire protection measures such as wearing fire-resistant coats to prevent external fires. Large foreign companies (BP, BASF, SHELL) have such requirements. The gas circuit may also require “online testing,” such as testing it once a year to check whether it functions properly. 3. It is basically a SIL circuit, including solenoid valves. 4. Since it involves cutting first and then performing a BLOWDOWN, the action time is short, so speed is required. Instead, a flow-limiting orifice plate is installed downstream of the valve to prevent too rapid discharge from causing excessive vaporization of hydrocarbons inside the equipment and resulting in overpressure; this is done to address concerns regarding the large discharge capacity of the safety valve. @jiaguoyun