What is a safety relief valve?

A safety valve or pressure relief valve (PRV) is a safety valve used to control or limit system pressure; otherwise, excessive pressure could build up and cause process upsets, instrument or equipment failure, explosions, or fires.

Types:

1. Conventional safety relief valve
2. Balanced safety relief valve
3. Pilot operated safety relief valve

Applications:

1. Conventional safety relief valve：

• In general gas, volatile gas, water vapor, air or liquid refining equipment;
• In corrosive refining equipment;
• When valve discharge must be piped to a remote location

2. Balanced safety relief valve

• Used for general gas, volatile gas, water vapor, air or liquid media in refineries;
• In refining equipment with corrosive media;
• When emissions must be discharged to remote locations through drain pipes.

3. Pilot operated safety relief valve

• Where there is significant pressure relief in high-pressure installations, as many pilot valves can be set at the highest pressure at the inlet flange;
• Where the difference between the working pressure of the container and the opening pressure of the valve is very small;
• On large low pressure storage tanks;
• Places that require short-term venting;
• Positions where back pressure is high and a balanced design is required, since a pilot valve with a pilot element open to the atmosphere can be fully balanced;
• Economical to use and general process equipment;
• Process conditions require pressure sensing at one location and liquid discharge at another location