MECHANICAL REFRIGERATING APPARATUS OF THE COMPRESSOR-CONDENSER-EXPANDER TYPE, AND PARTS AND FITTINGS THEREOF AND ENCLOSING CABINETS THEREFOR, THE SAME CONSISTING OF: SELF-CONTAINED WATER COOLERS OF PRESSURE AND BOTTLE TYPES THAT COMPRISE COOLING UNIT (CONSTITUTING REFRIGERANT EXPANDER) MOTOR DRIVEN COMPRESSOR, CONDENSER, AND ENCLOSING CABINET; WATER AND BEVERAGE COOLING UNITS (REFRIGERANT EXPANDERS) AND MOUNTING BASES AND CABINETS FOR SUCH WATER COOLING UNITS; COOLER-CARBONATORS IN THE FORM OF UNITARY DEVICES FOR CHARGING LIQUID WITH CO2 GAS AND COOLING THE LIQUID CHARGED; CABINETS AND PUMP-MOTOR-RELAY ASSEMBLIES FOR SAID COOLER-CARBONATORS; REFRIGERATED PHOTOGRAPHIC SINKS; WATER AND BEVERAGE COOLER PARTS CONSISTING OF REFRIGERANT CONTROL VALVES; AND FITTINGS FOR THE SAID REFRIGERATING APPARATUS CONSISTING OF OIL SEPARATORS (FOR SEPARATING OIL FROM REFRIGERANT), ADAPTOR-BLOCK ASSEMBLIES FOR SAID OIL SEPARATORS, ACCUMULATOR-INTERCHANGERS (FOR ACCUMULATING UNEVAPORATED REFRIGERANT AND INTERCHANGE OF HEAT BETWEEN CASEOUS AND LIQUID REFRIGERANT), REFRIGERANT EQUALIZER TANKS, AND CONNECTOR TUBES FOR THE WATER AND BEVERAGE COOLERS AND COOLER-CARBONATORS