Hose/Line HVAC: Description and Operation

- The mixture of refrigerant oil (PAG oil) and refrigerant R-134a attacks some metals and alloys (for example, copper) and breaks down certain hose material. Use only hoses and lines which are identified with a green mark (stripe) or the lettering "R-134a"
- Hoses and lines are secured with threaded connections. Always properly torque hose and line connections