Patent ID: 7866172

Claim:
A vapor compression air conditioning system, comprising: a compressor, a condenser, a low pressure working fluid conduit and a high pressure working fluid conduit connected to said system in a substantially closed circuit for conducting working fluid, the high pressure working fluid conduit being connected to a working fluid discharge of the condenser, a pressure sensor connected to the high pressure working fluid conduit, the pressure sensor being configured to measure a pressure of the working fluid within the high pressure working fluid conduit, a temperature sensor connected to the high pressure working fluid conduit, the temperature sensor being configured to measure a temperature of the working fluid within the high pressure working fluid conduit, and a working fluid flow restrictor associated with at least one of said low pressure working fluid conduit and high pressure working fluid conduit, the flow restrictor comprising: a housing; a first end face and a second end face within the housing; a plug movable within a passage in communication between the first and second end faces; a seat in the housing between the plug and the second end face, wherein the seat and the plug are arranged such that when the plug engages the seat, flow from the first end face to the second end face is restricted; and the working fluid flow restrictor being configured to control flow of the working fluid between said circuit and a working fluid reservoir of a working fluid charging apparatus in response to said measured temperature and pressure of the working fluid within the high pressure working fluid conduit.