Pressure and/or vacuum relief valves are used on liquid storage tanks and other process vessels or systems to prevent structural damage due to excess internal pressure or vacuum.
Storage tanks are pressurised when liquid is pumped in and compresses the existing vapour or when increasing temperature causes increased evaporation or expansion of existing vapour.
Conversely, vacuum may be created when pumping out or decreasing temperature. To prevent damage, vapour must be allowed to escape or enter the tank at a specified pressure or vacuum. The volume rate of venting depends upon the tank size, volatility of the contents, the pumping rate, and the temperature. See API Standard 2000 for the procedures to determine venting requirements.
There are 3 types of Pressure / Vacuum Relief Valves:
Pressure or Vacuum Relief Valves – Weight-Loaded, Spring-Loaded
Pressure or Vacuum Relief Valves – Air Operated
Get in touch
Valve Technology Ltd