Description:Cat® Expansion Valve controls the flow of refrigerant within HVAC lines to maintain pressures and function of the air conditioning unit. Cat components make certain that your equipment is operating at an optimal level.Application:Cat® Expansion Valves control the amount of refrigerant released into the evaporator controlling superheat in HVAC systems of heavy-duty equipment. Consult your owner's manual or contact your local Cat dealer for more information.