Txv Expansion Valve

Question 1

What does TXV stand for?

Answer 1

Thermostatic Expansion Valve

Receives high pressure liquid from the receiver-dryer.

Question 2

What does the temperature sensing bulb control?

Answer 2

Actuation of the TXV to meter the correct amount of refrigerant into the evaporator.

The TXV divides the A/C System. A high pressure liquid enters, low pressure liquid exits into the evaporator.

Question 3

What can cause the TXV to be misdiagnosed?

Answer 3

Low refrigerant charge (low low-side pressure, or even a vacuum), or contamination in the system.

You can see the TXV is functional when the low side pressure gauge is ‘wagging’ indicating opening/closing.

Question 4

What are some components of the TXV?

Answer 4

Power Element, Internal Equalization Passage, Sealed Temp Sensing Bulb, Operating Pin, Metering Orifice, Spring

High Pressure Subcooled Liquid, Low Pressure Liquid To Evaporator Inlet, Evaporator Outlet, Superheated Vapor to Compressor Suction