Pilot operated evaporator pressure regulator valve

Abstract

Abstract THE INTERIOR OF THE BELLOWS IS SEALED AT ATMOSPHERIC PRESSURE SO THE PRESSURE ON THE OUTSIDE OF THE BELLOWS IS RESISTED BY THE ATMOSPHERIC PRESSURE WITHIN THE BELLOWS AS WELL AS BY THE SPRING. WHEN THE PRESSURE ON THE OUTSIDE OF THE BELLOWS (WHICH IS EVAPORATOR PRESSURE IN A REFRIGERATION SYSTEM) EXCEEDS A PREDETERMINED AMOUNT, THE BELLOWS TENDS TO COLLAPSE AND THE HEAD OF THE BELLOWS PULLS AWAY FROM THE ACTUATING PIN AND ALLOWS THE SPRING ACTING ON THE PILOT VALVE TO OPEN THE PILOT VALVE WHEREUPON THE PRESSURE TO THE RIGHT OF THE HEAD OF THE PISTON IS REDUCED, ALLOWING THE PISTON TO MOVE TO THE RIGHT AGAINST THE RETURN SPRING FORCE AND, THUS, OPEN THE OUTLET BY REGISTERING THE PORT IN THE PISTON WALL WITH THE SLOT IN THE STATIONARY SLEEVE. WHEN THE PRESSURE FALLS BELOW THE DESIRED AMOUNT, THE BELLOWS EXPANDS AND MOVES THE HEAD OF THE BELLOWS AGAINST THE ACTUATING PIN TO CLOSE THE PILOT VALVE. LEAKAGE BETWEEN THE PISTON AND SLEEVE TO THE PILOT VALVE CHAMBER RAPIDLY RAISES THE PRESSURE THEREIN SO THAT THE RETURN SPRING CAN MOVE THE PISTON TO CLOSE THE OUTLET. EVEN WITH THE OUTLET CLOSED, THE SLIGHT CLEARANCE BETWEEN THE PISTON AND SLEEVE ALLOWS SOME REFRIGERANT FLOW TO INSURE ADEQUATE FLOW TO THE COMPRESSOR TO KEEP THE COMPRESSOR LUBRICATED.

Inventors

• 👤 Charles D Orth

Bibliographic Details