Thermal Relief Valve 3/8" MNPT 140 degree F | PN 5400022

Thermal relief valve with 3/8" MPT threads; discharges at 140 degrees fahrenheit.

Thermal Relief Valves protect your pump from overheating while in bypass.  Pressure Washer pumps are cooled by the water that passes thru them.  When you stop spraying the pump stops getting fresh water to cool it.  The thermal relief valve will discharge water from the pump if it reaches 140 degrees fahrenheit, allowing fresh water to enter the pump.  If your thermal relief valve is leaking it should be changed right away to prevent pump damage.