DOROT 68-710

DOROT 68-710, is used as both a 2-way, Diaphragm-actuated, Spring-loaded Pressure Sustaining Pilot Valve, designed for control of hydraulic valves, and as a 3-way Adjustable Relay Valve. For pressure sustaining, the pilot valve modulates to keep a steady, preset pressure upstream of its location.
Operation principle
As upstream pressure rises above the preset value, the pilot opens a water passage between the 4 and 3 ports. This allows water in the main valve chamber to vent to the downstream, causing the main valve to open. As the downstream pressure falls below the preset point, the pilot valve throttles the internal passage, restricting flow out from the main valve control chamber; enabling the valve to keep its position or to close, if necessary.