Hm-sp Pressure Sustaining Valve

The valve maintains downstream pressure over a pre-set minimum value, regardless of fluctuating flow or varying upstream pressure. Otherwise the valve may open gradually to allow surplus water flow outside the system in order to maintain system pressure to a maximum pre-set value. A hydraulic regulating pilot drives the valve. The pilot is able to detect upstream pressure values and regulates closing steps of the valve until the pre-set pressure value is restored.