Dual-piloted thermostatically controlled diaphragm valve

Claim 1

A FLUID VALVE FOR CONTROLLING THE FLOW OF FLUID FROM AN INLET TO AN OUTLET IN RESPONSE TO THE OPERATION OF A NORMALLY CLOSED PRESSURE RESPONSIVE DIAPHRAGM POSITIONED BETWEEN A MAIN CHAMBER AND SAID INLET, CONDUIT MEANS INTERCONNECTING SAID MAIN CHAMBER WITH SAID INLET TO ESTABLISH A PRESSURE EQUILIBRIUM THEREBETWEEN, FIRST AND SECOND AUXILIARY CHAMBERS EACH INCLUDING PASSAGE MEANS INTERCONNECTING SAID AUXILIARY CHAMBERS WITH SAID MAIN CHAMBER, A PAIR OF SEQUENTIALLY OPERABLE CONTROL VALVES INCLUDING A PAIR OF UNEQUALLY BIASED VALVE CLOSURES FOR CONTROLLING THE PASSAGE OF FLUID FROM SAID MAIN CHAMBER TO SAID AUXILIARY CHAMBERS THROUGH SAID PASSAGE MEANS, CONDUIT MEANS INTERCONNECTING SAID AUXILIARY CHAMBERS WITH SAID OUTLET, PRESSURE REGULATOR MEANS INCLUDED WITH EACH OF SAID AUXILIARY CHAMBERS TO CONTROL THE PRESSURE IN SAID OUTLET THROUGH THE LAST SAID CONDUIT MEANS, THE PRESSURE REGULATING MEANS FOR SAID SECOND CHAMBER BEING SET TO PROVIDE A HIGHER PRESSURE IN SAID OUTLET THAN THE PRESSURE REGULATING MEANS FOR SAID FIRST CHAMBER, THERMOSTATICALLY CONTROLLED ACTUATOR MEANS LINKED TO SAID CONTURE VARIATIONS TO SEQUENTIALLY OPERATE SAID CONTROL VALVES, WHEREBY FIRST AND SECOND PRESSURE DIFFERENTIALS BETWEEN SAID INLET AND SAID MAIN CHAMBER ARE SEQUENTIALLY ESTABLISHED BY THE PASSAGE OF FLUID FROM THE MAIN CHAMBER TO SAID AUXILIARY CHAMBERS, THE ESTABLISHMENT OF SAID PRESSURE DIFFERENTIALS MOVING SAID DIAPHRAGM FROM SAID CLOSED POSITION TO FIRST AND SECOND OPERATED POSITIONS SEQUENTIALLY.