Pressure relief valves protect fire sprinkler system components by relieving excess system pressure from supply surges or temperature changes. Since the 2010 edition, NFPA 13: “Standard for the Installation of Sprinkler Systems” has required pressure relief valves to be installed on all wet pipe fire sprinkler systems. But picking the correct relief valve for a specific system does need a little preplanning. By knowing the desired static pressure of the system and by reviewing the UL and FM standards regarding the required operational characteristic of relief valves used on sprinkler systems for guidance, one can deduce the best rating for a relief valve on any system.

While field-adjustable pressure relief valves may be tempting due to the flexible rating, they are often being used in a manner that violates the FM Standard. Their ability to be adjusted by anyone can introduce the very risks to the system that the NFPA 13 requirement was meant to eliminate. Factory-set relief valves are the best option due to a tested range of features proven to serve the system well.