Pressure relief and sustaining valve is a diaphragm type hydraulic control valve which uses the hydraulic pressure of the pipeline as the driving source. The main feature of the valve is that it can be used as both a pressure relief valve and a pressure sustaining valve.
As a safety pressure relief valve, it is used to release the high pressure in front of the valve that exceeds the set pressure of the valve out of the system pipeline, so as to prevent the high pressure or sudden pressure in the pipeline from damaging the pipeline and equipment in front of the valve; as a pressure sustaining valve, the water supply pressure upstream of the main valve can be maintained above a certain set value, so as to give priority to the water supply in the upstream area of the main valve.
