Pressure Relief Safety Valve


General Info

As an automatic safety relief valve, this valve is designed to operate in a pressure range from 2 to 35 PSI. Operation is fully automatic and no separate pilot connection to the tank is required. This valve will relieve excess pressure in the tank, or relieve a vacuum created in the tank with no special adjustments. Three interchangeable control springs permit pressure adjustments in the range of 12 to 35 psi, 5 to 18 psi, and low pressure 2 – 6 psi. This valve will handle both gas and liquid.

Fully Automatic Action

The valve will automatically open to relieve pressure in excess of that for which the valve is set. As soon as pressure is relieved, the valve automatically closes itself. There are no parts to be replaced or re-settings to be made after blow-off. Pressure level is adjusted by turning an adjusting screw. Liquids and gas remain under the adjusted pressure at all times. There is no unnecessary loss of CO2.


The valve may be tested at any time by depressing the manual control lever. The valve will immediately respond with an audible blow-off, and will close itself as soon as the lever is released. Repeated testing will not change the adjusted relief setting. The valve should be tested periodically just like any other safety equipment.


Valves are furnished in 316L stainless steel. The finish is machined inside and out. Diaphragms are availabe in neoprene (standard), gum rubber or silicone.


Should vacuum be created in the tank, the valve will automatically open to admit air into the tank. Having relieved the vacuum, the valve will immediately close itself.


Valves are available in sizes: 2”, 3” and 4”. Note, the port size of the valve (square area) should be equal to the line input of the tank.


Replacement parts are available for existing installations.


A straight female thread is recommended since this permits the placement of a sealing gasket between the orifice of the valve and the pipe connection to the tank. For new installations a stainless steel ferrule should be welded to the tank.