Reversible refrigerating system and control therefor

Claim 1

AN AUTOMATIC FLUID FLOW CONTROL VALVE COMPRISING A VALVE BODY HAVING A CYLINDER THEREIN, A VALVE PISTON MOUNTED FOR RECIPROCATING MOVEMENT IN SAID CYLINDER AND POSITIONED TO DIVIDE SAID CYLINDER INTO A CONTROL CHAMBER AND FLUID FLOW CHAMBER, AN INLET CONNECTION PROVIDING COMMUNICATION WITH SAID FLUID FLOW CHAMBER, AN OUTLET CONNECTION HAVING A VALVE SEAT POSITIONED FOR ENGAGEMENT WITH SAID PISTON TO PREVENT THE PASSAGE OF FLUID FROM SAID INLET THROUGH SAID OUTLET CONNECTION, A BLEED PASSAGE BETWEEN SAID INLET AND SAID CONTROL CHAMBER, MEANS PROVIDING COMMUNICATION BETWEEN SAID CONTROL CHAMBER AND SAID OUTLET CONNECTION, A PILOT VALVE FOR CLOSING SAID COMMUNICATION MEANS WHEREBY UPON OPENING OF SAID PILOT VALVE THE FLUID UNDER PRESSURE IS RELEASED FROM SAID CONTROL CHAMBER TO AFFORD OPENING OF SAID VALVE WHEN THE PRESSURE IN SAID FLOW CHAMBER EXCEEDS THE PRESSURE IN SAID OUTLET, AND A CHECK VALVE MOUNTED IN SAID COMMUNICATING MEANS TO PREVENT REVERSE FLOW OF FLUID THROUGH SAID COMMUNICATING MEANS TO SAID CONTROL CHAMBER WHEREBY SAID CONTROL VALVE IS OPENED UPON REVERSE FLOW CONDITIONS BETWEEN SAID OUTLET AND SAID INLET.