Item # A4454-4, Precision Relief Valve, 120 ± 10 PSI Max

Precision Relief Valves are used as a safety device on reservoirs where a certain maximum pressure should not be exceeded.  Their use can be extended to any application demanding pressure be relieved at a specific value.  The valves have a fixed upper pressure rating held within plus or minus 10 PSI accuracy.  The setting for the upper limit (120 ± 10 PSI) is tamperproof and cannot be adjusted.  The relief pressures can be reduced and locked at any setting.

This valve tolerates temperatures up to 225° F. It features a brass piston and Viton seals.  A plunger with an O-ring is seated against a port inside the aluminum valve body.  The plunger is held in place by a stainless steel spring.  An enclosure cap is screwed over the valve body and used to adjust the valve’s upper pressure limit.  A 3/32” diameter vent hole on the top of the cap allows the released air or liquid to escape. A locknut is provided on the valve body to lock the cap in place. The hex size is 3/4”.  The total height of the valve is 1 7/16”.

To use the relief valve at the maximum rated pressure of 120 ± 10 PSI, screw the top cap down until it is seated and lock this setting with the locknut.  To reset the valve for a lower pressure, back off the top cap to a suitable point that produces the desired pressure relief and lock the setting with the locknut.

The unit has a 1/4” NPT thread.