Three-way pressure switching valve - has spring loaded closure between inlet return and control for pressure chambers with throttled connections

摘要

The pressure switching valve has a housing containing a closure controlling the connection between an inlet and a return chamber and between the return chamber and a control chamber. The member has a first surface subjected to inlet pressure and a second surface of equal area subjected to the pressure in a pressure chamber. The member is moved to its rest position by a spring in the chamber. A duct leads from the inlet to the chamber via a throttle and to the chamber via a second throttle and there is a pilot valve between the chamber and the return. A third throttle is arranged between the chamber and the valve in series with the first two throttles.