R-12 Systems

R-12 refrigerant is colorless both as a gas and as a liquid. Since it boils (vaporizes) at -21.7°F, it will usually be in a vapor form when being handled in a repair shop. However, if a portion of liquid coolant should come in contact with hands or face, note that its temperature will be momentarily at least 22° below zero.

Protective goggles should be worn when opening any refrigerant lines. If liquid coolant does come into contact with eyes, rinse them out quickly in cold water, apply a bland disinfectant oil and see a physician as soon as possible.

When checking a system for leaks with a torch type leak detector, do not breathe vapors coming from flame. Do not discharge refrigerant near a live flame. A poisonous phosgene gas is produced when R-12 is burned. While a small amount of gas produced by a leak detector is not harmful unless inhaled directly at flame, the quantity of refrigerant released into the air when the system is purged can be extremely dangerous if allowed to come in contact with an open flame.

Never allow temperature of refrigerant containers to exceed 125°F. The resultant increase in temperature will cause a corresponding increase in pressure which may cause safety plug to release or drum to burst. If it is necessary to heat a drum of refrigerant when charging a system, drum should be placed in water that is no hotter than 125°F. Never use a blowtorch, or other open flame. If possible, a pressure release mechanism should be attached to the drum prior to heating.

Use care when disconnecting or connecting refrigerant lines, always use a back-up wrench and be careful not to over tighten any connection. Over tightening may result in line flare set distortion and a system leak.

When making pressure checks on system with intermediate valves, be sure valve is in the intermediate position. If turned in too far, hose connection will be closed, a position used for isolating the compressor. When closing gauge port, do not over tighten the valve or damage to valve seat will result.

After disconnecting gauge lines, check valve areas to be sure service valves are correctly seated and Schrader valves, if used, are not leaking.