The boiler pressure relief valve is a safety valve designed to relieved an excessive build up of pressure inside the boiler. The is a pressure vessel designed to handle a safe amount of pressure. If the pressure were to build up beyond the safety limitations as set forth by the design specifications the boiler system needs a safe way to vent the pressure to prevent an explosion. The boiler relief valve is this safe way to vent excessive dangerous pressures inside the boiler.
This pressure safety relief valve is piped into a nipple on the side of a Burnham boiler. The boiler relief valve also is piped to a drain so if the relief valve were to relieve or let go it would vent all the hot water to safe place away from people or electrical circuits. As part of a preventive maintenance plan these valves should be checked for seeping or dripping. Any boiler safety relief valve found dripping or seeping should be replaced. Most residential and light commercial hot water boilers have safety relief valves that will vent at 30 psi.
Boiler Pressure Relief Valve – Boiler Safety
How often should a residential steam boiler pressure relief valve be checked or tested for proper operation? How is the relief valve test performed? Is this a residential code requirement in New York City?
Not sure about NYC and as far as written in the code I am not aware of a code requirement test for a pressure relief valve as often times if you touch the old ones they will leak and need to be replaced. Most pressure relief valves have a tag and are certified by the manufacturer for the pressure rating on the valve. I spoke with a mechanical inspector about this and he was not aware of any code requirement for a periodic pressure relief valve inspection although he advised one may exist that he was not aware of.