Safety Relief Valves For Compressed Air

Safety relief valves prevent and protect against over-pressurization. The only expectation for this equipment is protection from over pressurized air. They are not to be used as a part of the process or as a pressure regulator. These units are fail-safes more than anything.

Over-pressurization occurs when the equipment exceeds its design pressure. In some instances, this pressure buildup can be so extreme that the equipment explodes. Having a safety relief valve in place prevents instances like this from occurring. As the system nears being over-pressurized, the safety relief valve opens and expels the excess until the desired pressure is reached. 

An example of when a safety relief valve is essential is during a power failure. In this situation, controls are nonexistent, and the excess pressure from the tank needs to be discharged. If you have a safety relief valve in place, it will automatically discharge the excess pressure. Without this relief valve, the pressure has nowhere to go and stays in the equipment. 

Selecting a Safety Relief Valve 

When you want to add a safety relief valve to your compressed air system, there are a few variables to be aware of:

• Type of Compressor
  • Depending on the type of air compressor in place, the PSI and CFM requirements can vary greatly. Compressors with a similar pump model can operate at different pressures and airflow intervals.
• Pressure per Square Inch (PSI) 
  • The PSI is the most crucial component of sizing a safety relief valve. If it is not sized properly, it will not be able to perform its job. Sizing your safety relief valve is necessary if you want it to function correctly. 
• Valve Size
  • The size of the relief valve is a rather crucial measurement. The valve must be large enough to handle the air being discharged. More extensive operations require larger safety relief valves.
• Industry Requirements
  • Depending on your industry, a safety relief valve may be required for your system. Multiple safety relief valves may even be required throughout the process.

Getting a Safety Relief Valve For Your System

When you select a safety relief valve for your compressed air system, make sure you are getting the right type. Safety relief valves are just one of three different types of pressure relief valves. They are a combination of Safety and Relief valves—who would have guessed? 

A safety valve is actuated by inlet static pressure and has a rapid opening or pop action. On the other hand, relief valves are actuated by inlet static pressure, but they lift gradually and proportionally to the increase in pressure. Safety relief valves are a combination of these two: they are actuated by static inlet pressure but can either pop open or gradually open with an increase in pressure. 

The differences between the safety relief valve models are negligible. They are your last line of defense against over pressurization, so whether they pop open or gradually open with the pressure difference, the end result is still the same. The crucial aspect of having a safety relief valve in place is making sure the pressure range is within the valve’s capability.