A recovery cylinder which is half full of recovered R-12 at normal room temperature (about 75F), in the absence of non-condensables, will be pressurized to:

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Multiple Choice

A recovery cylinder which is half full of recovered R-12 at normal room temperature (about 75F), in the absence of non-condensables, will be pressurized to:

When a closed cylinder contains liquid refrigerant and vapor at a given temperature, and there are no non-condensables, the pressure is governed by the saturated vapor pressure of that refrigerant at that temperature. The system reaches equilibrium so the vapor pressure matches the saturation pressure for R-12 at about 75°F. That value is about 95 psi gauge. The amount of liquid present (half full) doesn’t change this pressure as long as liquid and vapor coexist at this temperature. If non-condensables were present, the pressure would be higher than the saturation value, but without them, it sits at the saturation pressure corresponding to 75°F.

When a closed cylinder contains liquid refrigerant and vapor at a given temperature, and there are no non-condensables, the pressure is governed by the saturated vapor pressure of that refrigerant at that temperature. The system reaches equilibrium so the vapor pressure matches the saturation pressure for R-12 at about 75°F. That value is about 95 psi gauge. The amount of liquid present (half full) doesn’t change this pressure as long as liquid and vapor coexist at this temperature. If non-condensables were present, the pressure would be higher than the saturation value, but without them, it sits at the saturation pressure corresponding to 75°F.

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