canister 39 s second valve to provide a motive force for oil removal operation to a non operating compressor application_number US 9494793 A description the present invention relates to a closed loop oil service system used in conjunction with an ac or refrigerant compressor fig1 and 2 diagrammatically illustrate a closed loop oil removal system fig3 and 4 diagrammatically illustrate a closed loop oil augmentation system fig5 and 6 diagrammatically illustrate a closed loop calibrated oil augmentation system fig7 and 8 diagrammatically illustrate a cross sectional view of one type of canister and a cap respectively fig1 diagrammatically illustrates closed loop oil removal system 80 for recovering compressor lubricating oil 30 from operating compressor 12 operating compressor 12 includes compressor casing 14 sight glass or viewing port 16 refrigerant inlet port and valve 18 refrigerant outlet port and vane 20 and submerged oil drain port and vane 22 operating compressor 12 is illustrated as retaining a supply of lubricating oil 30 within compressor casing 14 closed loop oil removal system 80 includes fluidly and gaseously sealed canister 32 and first valve 36 having long stem 38 and port 40 located near the bottom of canister 32 canister 32 also includes second vane 42 having short stem 44 with port 46 located near.