What is a TX valves’ function?
A thermostatic expansion valve (TX Valve) controls the flow of liquid refrigerant into the evaporator. They have a variable metering orifice that opens and closes based on the outlet temperature and pressure of the evaporator coil.
Most passenger vehicle ac systems use block style TX valves.
What is Tonnage?
TX valves have a tonnage rating which refers to the capacity of the valve.
1 ton = 12,000 Btu/hr
What is Superheat and why is it important?
Superheat refers to the “extra heat” absorbed by refrigerant vapour after it has changed state inside the evaporator coil. It ensures all liquid refrigerant is evaporated which provides maximum thermal efficiency.
Most TX valves have a Superheat setting between 5-10°C.
Symptoms of a malfunctioning TX valve
What causes the evaporator lines to freeze?
Can a dirty TX valve be cleaned?
CoolDrive Auto Parts has a comprehensive range of OE and aftermarket TX valves available. Contact your local branch or view our entire range online!