A safety device mounted on a water heater or boiler. The relief valve is designed to release any high pressure in the vessel and thus prevent tank explosions.

A safety device which releases boiler and system pressure should it exceed a preset level. The normal pressure setting of these devices for the low pressure boiler is 30-45 PSI. The preset level should never exceed the operating pressure of the boiler.

Also known as a "pressure and temperature relief valve" or P.T.R Valve or T.P.R Valve or T & PR Valve. It is a device which automatically opens a relief vent when the pressure and/or temperature rises to a predetermined value and closes when the pressure and/ or temperature falls below this value.

is a mechanical device that eliminates system overpressure by allowing the controlled or emergency escape of liquid or gas from a pressurized system. The relief valve may or may not be adjustable.

Water heaters have a pressure relief valve. It's usually threaded sufficiently that when you're going closed system on the water heater, it's the best place to put water into the boiler tank. So, to fill the boiler, you screw the hose into the pressure relief valve then you open the pressure relief valve to let water enter. Then turn on the hose. The tank will begin to fill but it will require a way for air to leave the boiler tank! So you have to have a piece of pipe higher than the tank with a bleeder valve on it. Open the bleeder valve and you'll hear water going IN the pressure relief and air hissing out the bleeder valve you've installed. Click here for a picture of the bleeder valve I used.

a pressure relief device designed to reclose and prevent further flow of fluid after normal conditions have been restored

a safety device on a water heater pressure regulator valve water

a safety device that must be used if no demand valves are present on the regulator

a valve which opens when the pressure exceeds a pre-set point.

A device on an air compressor where the valve will open automatically to prevent over pressurization of the system.

Druckbegrenzungsventil: A valve, which limits the pressure to a pre-determined value by exhausting fluid.

Used on a hot water heater or boiler. This device is used to prevent the build-up of steam within the tank by releasing steam when pressure reaches a certain threshold.

A valve that releases pressure if needed. This valve is self-operating.

This type of valve opens automatically and relieves pressure in the pipeline, which keeps pressure at the desired levels.

A valve that opens and closes to ensure that pressure does not rise above a predetermined value.

A valve used on hot water heating appliances to help keep the pressure in the heated tank or boiler from getting too high by allowing the relief of pressure from the valve.

A device mounted on a hot water heater or boiler which is designed to release any high steam pressure in the tank and thus prevent tank explosions.

Valve to relieve excess pressure in water storage tanks

a valve that once it reaches a preset pressure or temperature point opens up to relieve the action

A valve that will open when the inlet pressure exceeds a preset pressure.

a valve that opens at a preset pressure to relieve excessive pressures within a vessel or line. Also called a relief valve, safety valve, or safety relief valve.

A safety vent that relieves excess pressure in a water heater.

A safety valve on the water heater that allows cold water in the tank and discharges hot water if the tank overheats or if excessive pressure exists. This is done by allowing the hot water to discharge from the heater.

A pressure-actuated valve held closed by a spring or other means and designed to relieve pressure automatically in excess of the device's setting.

A type of pressure relief device designed to open and close to maintain internal fluid pressure. Pressure relief valves are divided into the following types: External Pressure Relief Valve, Flush Type Full Internal Pressure Relief Valve, Full Internal Pressure Relief Valve, Internal Spring-Type Pressure Relief Valve, and Sump-Type Full Internal Pressure Relief Valve.