When filter vessels are manufactured they are designed at a set pressure and undergo strict approval processes. It is therefore vital that any excess pressure build up needs to be removed from the system quickly and safely. One of the main causes of pressure increase is thermal expansion from hot temperatures. As the vessels are usually in outdoor ambient conditions, there is a high possibility of this happening especially during the warmer months. The pressure relief valves are designed to release any excess pressure in the system and close when it is below the set pressure. These valves are sometimes used together with a “show flow” valve to confirm that pressure is being relieved
Please note that these relief valves are only designed to handle normal thermal stresses. Further consideration must be made to account for other pressure increase incidents including surges and fires.