AC lines are fluid-carrying components within a vehicle’s air conditioning system, connecting the compressor, condenser, evaporator, and receiver/drier. Constructed from steel or aluminum alloy tubing, these lines must withstand high pressures and temperatures while maintaining leak-free performance. Fittings utilize standardized O-ring or flare connections, requiring precise tightening torque to ensure system integrity. Barrier hosed designs prevent permeation of refrigerant and maintain cooling efficiency. Replacement lines meet OEM specifications for diameter, bend radius, and material compatibility.