Abstract: An air conditioning service system includes a discharge unit including a discharge vessel, a vacuum pump fluidly connected to the discharge vessel, a scale configured to sense a weight of the discharge unit, a first valve arranged in an input line configured to fluidly connect the discharge vessel to an air conditioning system, and a vent valve arranged in a vent line and configured to fluidly connect the discharge vessel to the atmosphere. A controller operates the vacuum pump to evacuate the discharge vessel, obtains an evacuated weight of the discharge unit, operates the first valve to open to fill the discharge vessel with refrigerant, obtains a filled weight of the discharge unit, operates the vent valve to vent refrigerant from the discharge vessel, obtains a vented weight of the discharge unit, and determines a mass of refrigerant vented based upon the stored evacuated, filled, and vented weights.

Abstract: An air conditioning service system includes a discharge unit including a discharge vessel, a vacuum pump fluidly connected to the discharge vessel, a scale configured to sense a weight of the discharge unit, a first valve arranged in an input line configured to fluidly connect the discharge vessel to an air conditioning system, and a vent valve arranged in a vent line and configured to fluidly connect the discharge vessel to the atmosphere. A controller operates the vacuum pump to evacuate the discharge vessel, obtains an evacuated weight of the discharge unit, operates the first valve to open to fill the discharge vessel with refrigerant, obtains a filled weight of the discharge unit, operates the vent valve to vent refrigerant from the discharge vessel, obtains a vented weight of the discharge unit, and determines a mass of refrigerant vented based upon the stored evacuated, filled, and vented weights.

Abstract: A refrigerant recovery unit is provided that can recover and recharge refrigerant. The unit is further configured with a pair of service hoses and a refrigerant control circuit operable to receive and transport the refrigerant between the hoses and the storage vessel and to process the refrigerant to substantially remove contaminants from the refrigerant. A fluid connector is provided in fluid communication with the hoses to enable the refrigerant to flow between the hoses and to establish a closed loop through the refrigerant control circuit, and a controller is operatively connected to the refrigerant control circuit and configured to control a flow of the refrigerant through the refrigerant control circuit and through the fluid connector.

Abstract: A refrigerant recovery unit is provided that can recover and recharge refrigerant. The unit is further configured with a pair of service hoses and a refrigerant control circuit operable to receive and transport the refrigerant between the hoses and the storage vessel and to process the refrigerant to substantially remove contaminants from the refrigerant. A fluid connector is provided in fluid communication with the hoses to enable the refrigerant to flow between the hoses and to establish a closed loop through the refrigerant control circuit, and a controller is operatively connected to the refrigerant control circuit and configured to control a flow of the refrigerant through the refrigerant control circuit and through the fluid connector.

Abstract: A refrigerant recovery unit is provided that can clear oil from an oil inject path in order to prepare the unit to switch over to a different kind of oil. The refrigerant recovery unit includes an oil inject circuit that receives an oil from the oil bottle into the refrigerant system. The refrigerant recovery circuit is coupled in fluid communication with the oil inject circuit. The refrigerant recovery circuit is operable to receive and transfer a fluid drawn through the oil inject circuit. A controller is operatively connected to the refrigerant recovery circuit and to the oil inject circuit so that as the fluid is drawn through the oil inject circuit a quantity of the oil in the oil inject circuit is removed.

Abstract: A refrigerant recovery unit is provided that can recover and recharge refrigerant. The unit is further configured with a pair of service hoses and a refrigerant control circuit operable to receive and transport the refrigerant between the hoses and the storage vessel and to process the refrigerant to substantially remove contaminants from the refrigerant. A fluid connector is provided in fluid communication with the hoses to enable the refrigerant to flow between the hoses and to establish a closed loop through the refrigerant control circuit, and a controller is operatively connected to the refrigerant control circuit and configured to control a flow of the refrigerant through the refrigerant control circuit and through the fluid connector.

Abstract: A refrigerant recovery unit is provided that can clear oil from an oil inject path in order to prepare the unit to switch over to a different kind of oil. The refrigerant recovery unit includes an oil inject circuit that receives an oil from the oil bottle into the refrigerant system. The refrigerant recovery circuit is coupled in fluid communication with the oil inject circuit. The refrigerant recovery circuit is operable to receive and transfer a fluid drawn through the oil inject circuit. A controller is operatively connected to the refrigerant recovery circuit and to the oil inject circuit so that as the fluid is drawn through the oil inject circuit a quantity of the oil in the oil inject circuit is removed.

Abstract: A conduit is coupled to an oil accumulator with an orifice coupled in series with the conduit for limiting the flow of oil therethrough. A pressure sensor is coupled to the conduit for measuring the pressure in the conduit. An oil drain control solenoid valve is coupled to an electrical circuit also coupled to the pressure sensor for selectively opening the oil drain for the draining of oil into a collection tank without losing refrigerant.

Abstract: Conduits are coupled to a supply tank of refrigerant to allow the sensing of the amount of air present in the refrigerant tank and, upon the detection of air, the purging of air from the tank with a minimal loss of refrigerant. Preferably, the conduits include flow restrictors such as orifices and solenoid valves controlled by a microprocessor to sequentially sample and purge air from the refrigerant tank as required.

Abstract: A refrigerant servicing system includes a main supply tank of refrigerant and an auxiliary tank which is coupled to the main tank by a valve which is selectively controlled by a circuit also coupled to weight and pressure sensors to assure the main tank has a level of refrigerant adequate for providing a continuous supply of refrigerant during servicing.

Abstract: A lift assembly which is coupled to a refrigerant service cart to raise and lock the supply tank of refrigerant off of a weight sensor, locking the tank in a raised position for transportation of the portable servicing cart. In a preferred embodiment, a fixed arm extends from the portable cart and is positioned at a location above the refrigerant tank. A movable connecting link extends from the arm and is coupled to the tank and is controlled by an over-center toggle with a control handle for raising and lowering the tank coupled to the link between a use position resting on the weight sensor and a transporting position engaging the fixed arm and locked thereto by the over-center toggle control.

Abstract: In a refrigerant recovery system, a refrigerant compressor has an inlet for connection to a source of refrigerant to be recovered and an outlet for connection to a refrigerant storage container. A separator is connected in series with the compressor for separating lubricant from refrigerant either before or after passage of the refrigerant through the compressor. A valve or other suitable means is operatively connected between the inlet and outlet of the compressor for equalizing pressure across the compressor during non-operation of the compressor. A pressure sensor is coupled to the refrigerant recovery system and responsive to refrigerant pressure at the lubricant separator. A manual or automatic valve is coupled to a drain on the separator for draining lubricant from the separator during non-operation of the compressor when refrigerant pressure at the separator reaches a selected level during non-operation of the compressor.

Abstract: A refrigerant handling system that is particularly adapted for flammable or potentially flammable refrigerants that includes a compressor having an inlet for connection to a source of refrigerant, and a condenser connected to the outlet of the compressor for at least partially condensing refrigerant passing therethrough. An air motor is connected to a source of air under pressure for operating the compressor. The air from the motor exhaust is directed to the condenser for cooling the condenser and thereby enhancing extraction of heat from refrigerant passing through the condenser.

Abstract: A system for recovering at least two different and incompatible types of refrigerant that includes a compressor having an inlet for connection through first and second parallel inlet paths to equipment under service, and an outlet for connection through first and second parallel outlet paths to refrigerant storage containers. The first inlet and outlet paths terminate in connector fittings of a first configuration, and the second inlet and outlet paths terminate in connector fittings of a second configuration different from the first. Solenoid valves are associated with the inlet and outlet paths, and are actuated alternately so that the inlet and outlet paths are not simultaneously connected to the compressor. The connector fittings are mounted on a panel that has a sliding door for selectively exposing either but not both sets of connector fittings. The chance of misconnection and mixing refrigerant types is thereby reduced.

Abstract: A vacuum pump that includes an electric motor and a pump module mounted to the motor housing with the motor shaft being rotatably coupled to a pumping mechanism within the pump module. A pump inlet and a pump outlet are respectively coupled to the pumping mechanism within the pump module for pumping air from the inlet to the outlet upon operation of the motor. An inlet valve is carried by the pump, and is selectively movable by an operator between an open position in which the pump inlet port is coupled to the pumping mechanism and a closed position in which the inlet port is isolated from the pumping mechanism. In this way, the pumping mechanism may be connected to a system under service by placing the inlet valve in the open position to evacuate the system, and may be isolated from the system under service without disconnection therefrom by placement of the inlet valve in the closed position during service on or charging of the system.

Abstract: A refrigerant recovery and purification system that includes a refrigerant compressor having an inlet for connection to refrigeration equipment under service from which refrigerant is to be recovered. The outlet of the compressor is connected through a condenser to a refrigerant storage vessel or container, with the condenser at least partially liquifying refrigerant prior to passage to the storage container. A liquid refrigerant pump is connected for selectively circulating refrigerant in liquid phase in a closed path from the storage container through a filter for removing contaminants from the refrigerant, and then through the condenser back to the storage container. Refrigerant circulated by the liquid pump in the closed path is thus simultaneously purified by passage through the filter and cooled by passage through the condenser.

Abstract: Apparatus for identifying and distinguishing between at least two different types of refrigerant includes a sample container having a fixed internal volume. Refrigerant to be tested is selectively admitted into the container in vapor phase, vapor pressure of refrigerant within the container is measured, and admission of refrigerant into the container is terminated when the vapor pressure of refrigerant contained therein reaches a preselected level. A sensor and associated electronics are coupled to the container for determining type of refrigerant vapor in the container as a function of one or more selected properties of the refrigerant, and indicating such refrigerant type to the operator.

Abstract: A refrigerant handling system that includes a compressor and a condenser, each having an inlet and an outlet, with the condenser inlet normally being connected to the compressor outlet so that refrigerant in vapor phase from the compressor is at least partially condensed in the condenser. To clear liquid refrigerant from the condenser, the compressor outlet is disconnected from the condenser and connected to a refrigerant storage container, and the condenser outlet is connected to the compressor inlet. The compressor is then operated to draw refrigerant in vapor phase from the condenser, and to feed such refrigerant to the refrigerant storage container bypassing the condenser. A gauge is coupled to the compressor inlet so that compressor operation may be terminated by the operator when refrigerant vapor pressure in the condenser drops below a preselected threshold level. Thus, the condenser is cleared of refrigerant, which is now stored in the refrigerant storage container.

Abstract: An electronic scale assembly for transferring refrigerant charge between a tank and refrigeration equipment under service comprises a generally rectangular enclosure that includes a handle positioned along one side edge of the enclosure for manually transporting the scale, and a cover for selectively opening and closing the enclosure. A scale includes a platform mounted within the enclosure at a position to support a refrigerant tank when the cover is open, and a strain gage sensor for providing an electrical signal as function of weight supported by the platform. A solenoid-operated refrigerant transfer valve is mounted within the enclosure for connection between a tank mounted on the scale platform and refrigeration equipment under service for selectively transferring refrigerant between the tank and the equipment through the valve. An electronic controller is responsive to the electrical scale signal for indicating weight of refrigerant transferred through the valve.

Abstract: Apparatus for service and recharge of refrigeration equipment, with particular application to automotive air conditioning equipment. A vacuum pump, and oil and refrigerant charge containers are housed within a portable enclosure and configured for selective connection by electrically operated solenoid valves to refrigeration equipment under service. The refrigerant and oil containers are carried by a scale which provides electrical outputs signals as a function of weight of refrigerant and oil remaining in the containers. A microprocessor-based controller receives the scale signals and control signals from an operator panel for automatically cycling through vacuum, oil charge and refrigerant charge stages in a programmed mode of operation. The microprocessor-based controller includes facility for operator programming of the vacuum time and oil and refrigerant charge quantities, and for self- or operator-implemented diagnostics. Operating conditions and stages are displayed at all times to the operator.