Abstract: Apparatus for protecting a fluid sensor against excess fluid pressure that includes a manifold having an internal fluid passage and a fluid inlet for connecting the passage to a fluid system. A piston is disposed within the passage adjacent to one end of the passage, and a rod extends from the piston through the passage. A valve is coupled to the rod at a position spaced from the piston, and is cooperable with the passage for selectively terminating fluid flow through the passage. A fluid sensor may be mounted on the manifold for communicating with fluid in the passage at an end thereof adjacent to the valve and remote from the piston. A spring resiliently engages the piston and urges the piston, rod and valve toward the end of the passage to open the valve. Fluid pressure at the inlet sufficient to overcome forces applied to the piston by the spring functions to close the valve and thereby to isolate the sensor from the fluid inlet.

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: Refrigerant is purified by circulating the refrigerant in a closed path from a first refrigerant container through a filter/dryer unit back to the first refrigerant container. Air and other non-condensibles are purged from the refrigerant in the first storage container during this refrigerant circulation process. Following the non-condensible purging operation, the refrigerant in the first container is transferred through a filter/dryer unit into a second refrigerant container. This second refrigerant container is evacuated prior to transferring the purified refrigerant thereto. Capacity of the filter/dryer unit is monitored, either by monitoring time of operation of the refrigerant pump or monitoring wetness of the circulated refrigerant with the sight gauge.

Abstract: A refrigerant handling system that includes a chamber for holding refrigerant, and a refrigerant pump for directing refrigerant into the chamber so that the refrigerant collects in liquid phase at a lower portion of the chamber while air and other non-condensibles collect in vapor phase at the upper portion of the chamber over the refrigerant. Sensors are responsive to temperatures of the refrigerant entering the chamber and of the refrigerant collected in the lower portion of the chamber. Partial pressure of non-condensibles in the upper portion of the chamber is determined as a function of a difference between such temperatures, and the non-condensibles are purged from the upper portion of the chamber when such partial pressure reaches a selected threshold.

Abstract: A refrigerant handling system that includes a refrigerant compressor having an inlet for connection to a source of refrigerant and an outlet for delivering refrigerant under pressure. A refrigerant/non-condensible separator is coupled to the compressor outlet. The separator includes a refrigerant conduit wound in a closed planar spiral, such that refrigerant flowing through the conduit is urged by centrifugal force against the radially outer wall portion of the conduit. Openings in the upper wall portion of the conduit vent air and other non-condensibles of lesser molecular weight than the refrigerant.

Abstract: A refrigerant handling system that includes an air purge chamber and a refrigerant pump for directing refrigerant into the air purge chamber so that the refrigerant collects in liquid phase at a lower portion of the chamber while air and other non-condensibles collect in the vapor space at the upper portion of the chamber over the liquid refrigerant. A purge valve is connected to the upper portion of the chamber for automatically or manually purging air and other non-condensibles from the chamber. A refrigerant outlet is positioned at the lower portion of the chamber for drawing liquid phase refrigerant from the chamber. Desiccant adsorbent material is disposed in a canister connected to the upper portion of the air purge chamber for adsorbing refrigerant vapor in air passing through the canister. The desiccant adsorption material thus prevents venting of refrigerant vapor with non-condensibles from the air purge chamber.

Abstract: A thermoelectric refrigerant handling system that includes a chamber having an inlet path for receiving refrigerant from a source thereof and an outlet for delivering refrigerant in vapor phase. A thermoelectric element is operatively disposed between the chamber and the refrigerant inlet path, and is responsive to application of electrical energy for transferring heat from the inlet path to the chamber. In this way, heat is withdrawn from refrigerant at the inlet path and refrigerant is drawn into the inlet from the source, while heat is added to refrigerant in the chamber until the refrigerant is vaporized and driven by vapor pressure through the chamber outlet. A controller applies electrical energy to the thermoelectric element for transferring heat into the chamber to vaporize the refrigerant contained therein until the chamber is substantially empty of refrigerant, and then opens a valve to feed refrigerant from the inlet path to the chamber.

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: One or more properties of a refrigerant are analyzed by evacuating a refrigerant sample vessel, drawing a refrigerant vapor sample into the vessel, and condensing the refrigerant sample within the vessel for measurement and indication of one or more desired properties of the liquid refrigerant sample. By drawing the sample refrigerant in vapor phase rather than liquid phase, the sample will be relatively free of lubricant, particulate or water contamination. The sample vessel can be readily cleaned by simple evacuation in preparation for the next measurement cycle.

Abstract: Apparatus for purification of refrigerant that includes a replaceable filter/dryer unit for removing water from refrigerant passing therethrough and having a predetermined water absorption capacity, and a compressor for pumping refrigerant through the filter/dryer unit. Refrigerant vapor pressure is measured at the compressor inlet, and mass flow rate of water in the refrigerant pumped through the filter/dryer unit is determined as a function of measured pressure. The mass flow rate of water so determined is monitored over time of operation of the refrigerant pump to determine when the mass of water in refrigerant pumped through the filter/dryer unit reaches the predetermined water absorption capacity of the unit. Filter status may be indicated to an operator and/or operation of the pump may be terminated.

Abstract: Refrigerant type is identified and determined by storing in electronic memory indicia representative of saturation pressure/temperature characteristics of a plurality of differing refrigerant types. A liquid refrigerant sample of unknown type is obtained and vaporized under controlled conditions of temperature and pressure. Refrigerant vapor temperature is measured at two different vapor pressures during the vaporization process, and such temperatures and pressures are then compared with the indicia prestored in memory. Two temperature readings at differing vapor pressures are sufficient to distinguish refrigerant type based upon the prestored saturation/temperature indicia.

Abstract: A refrigerant handling system that includes an air purge chamber and a refrigerant pump for directing refrigerant into the air purge chamber so that the refrigerant collects in liquid phase at a lower portion of the chamber while air and other non-condensibles collect in a vapor space at the upper portion of the chamber over the refrigerant. A purge valve is connected to the upper portion of the chamber for automatically or manually purging air and other non-condensibles from the chamber. A refrigerant outlet is positioned at the lower portion of the chamber for drawing liquid phase refrigerant from the chamber. A minimum level of liquid phase refrigerant is maintained in the lower portion of the chamber at the outlet isolating the outlet from the vapor space, and preventing removal of air and other non-condensibles from the chamber through the outlet.

Abstract: One or more properties of a refrigerant are analyzed by evacuating a refrigerant sample vessel, drawing a refrigerant vapor sample into the vessel, and condensing the refrigerant sample within the vessel for measurement and indication of one or more desired properties of the liquid refrigerant sample. By drawing the sample refrigerant in vapor phase rather than liquid phase, the sample will be relatively free of lubricant, particulate or water contamination. The sample vessel can be readily cleaned by simple evacuation in preparation for the next measurement cycle.

Abstract: A refrigerant handling system that includes an air purge chamber and a refrigerant pump for directing refrigerant into the air purge chamber so that the refrigerant collects in liquid phase at a lower portion of the chamber while air and other non-condensibles collect in a vapor space at the upper portion of the chamber over the refrigerant. A purge valve is connected to the upper portion of the chamber for automatically or manually purging air and other non-condensibles from the chamber. A refrigerant outlet is positioned at the lower portion of the chamber for drawing liquid phase refrigerant from the chamber. A minimum level of liquid phase refrigerant is maintained in the lower portion of the chamber at the outlet isolating the outlet from the vapor space, and preventing removal of air and other non-condensibles from the chamber through the outlet.

Abstract: A refrigerant recovery system that includes a compressor having an inlet and an outlet, and an oil separator connected to the compressor inlet for separating oil from refrigerant recovered from equipment under service. A check valve is connected between a vapor outlet port on the oil separator and the inlet of the compressor for feeding refrigerant directly to the compressor inlet. A pressure sensor is connected to the oil separator for indicating refrigerant vapor pressure within the separator, and a valve is automatically responsive to such refrigerant vapor pressure for connecting a vacuum pump between the oil separator vapor port and the compressor inlet in parallel with the check valve when refrigerant vapor pressure at the oil separator falls below a predetermined value.

Abstract: A refrigerant handling system that includes a closed vessel for storing refrigerant and an apparatus for determining quantity of air captured within the vessel. A first sensor is operatively coupled to the vessel for providing a first electrical signal as a function of air/refrigerant vapor pressure within the vessel, and a second sensor is operatively coupled to the vessel for providing a second electrical signal as a function of air/refrigerant vapor temperature within the vessel. A microprocessor-based controller has internal memory in which electronic indicia is stored for relating saturation pressure to temperature for multiple types of refrigerant. This stored electronic indicia is employed in conjunction with the first and second sensor signals to determine quantity of air within the vessel as a function of a difference between pressure indicated by the first sensor signal and the saturation pressure indicia at the temperature indicated by the second sensor signal.

Abstract: A refrigerant handling system that includes a compressor and an evaporator for adding heat to refrigerant fed to the compressor inlet. A first condenser is connected to the compressor outlet and disposed in heat exchange relationship to the evaporator for at least partially condensing refrigerant vapor from the compressor outlet by transfer of heat to refrigerant in the evaporator. A second condenser is not in heat exchange relationship with the evaporator. The first and second condensers are connected in series with the compressor outlet, and one or more valves are connected to the second condenser for selectively bypassing refrigerant from the second condenser, while all refrigerant from the compressor outlet flows through the first condenser that is in heat exchange relation to the evaporator.

Abstract: A refrigerant handling system that includes a compressor for pumping refrigerant through the system, and an evaporator connected to the compressor inlet for ensuring that refrigerant fed to the compressor inlet is in vapor phase. A flow control device is coupled to the inlet of the evaporator for controlling flow of refrigerant to the evaporator, and comprises a thermostatic expansion valve having first and second pressure inputs, and valve elements for controlling flow of refrigerant through the valve to the evaporator as a function of a pressure differential between the pressure inputs. A first bulb containing refrigerant is sealingly coupled to the first pressure input of the valve, and is positioned so as to supply a first control pressure to the valve as a function of vapor pressure of refrigerant in the bulb at the temperature of refrigerant entering the evaporator.

Abstract: Apparatus for purification of a single refrigerant type, or of differing refrigerant types having differing density and moisture solubility characteristics, that includes a filter/drier unit for removing water from refrigerant passing therethrough and having a predetermined water absorption capacity. A refrigerant pump, such as a refrigerant compressor, pumps refrigerant through the filter/drier unit during recovery of refrigerant from equipment under service and/or in a separate refrigerant purification cycle. A flow meter is coupled to the filer/drier unit for measuring volumetric flow of refrigerant passing through the filter/drier unit. Volumetric flow of refrigerant through the flow meter is monitored over time for indicating to an operator when the filter/drier unit should be replaced as a function of mass of refrigerant pumped through the filter/drier unit and independent of types of refrigerant pumped through the filter/drier unit.