Properties of Refrigerant R502

Refrigerant 502 (R-502) is a liquid mixture of Refrigerant 22 (R-22) and Refrigerant 115 (R-115). It must be used in reciprocating compressors and is most often used to refrigerate frozen food display cases, frozen food walk-in refrigerators and equipment used to process frozen food. Its color-coded tank is orchid.

General Properties

R-502 is an azeotropic mixture, meaning that it maintains a constant minimum and maximum boiling point. R-502 has a molecular mass of 111.63. It boils at -5 degrees F when the atmospheric pressure is 14.7 pounds per square inch. R-502 is classed as a ChloroFluoroCarbon (CFS) refrigerant and is listed among the safest of the most commonly used refrigerants.

Chemical Composition

R-502 is a combination of 51.2 percent R-115 and 48.8 percent R-22. R-115, chloropentafluoroethane, is a colorless, pressurized liquid that boils at -38 degrees F. Its tank has no assigned color code.R-22, monochlorodifluorome-thane, is a synthetic refrigerant with a boiling point of -41 degrees F. The color code of a tank of R-22 is green.

Global Warming Potential

The Ozone Depletion Potention (ODP), the measure the relative degradation a refrigerant can cause to the atmosphere is .283 beginning at 0. The Global Warming Potential (GWP) with a base of 1 measures how much a given mass contributes to global warming. The GWP of R-502 is 4.1 These numbers are low compared to other refrigerants. For example, R-11, trichlorofluoromethane has an ODP of 1 and R-113, trichlorotrifluoroethane, has a GWP of 4,800.

Critical Points

A critical point is that temperature, pressure or volume beyond which a gas that is a liquid under pressure ceases to become a liquid. The critical temperature of R-502 is 180 degrees F. Its critical pressure is 591 pounds per square inch and its critical volume is .0286 cubic feet per pound.