Refrigeration and Air Conditioning Practice Test: Expansion Devices — Flashcards

Expansion devices are components of refrigeration and air conditioning systems that regulate the flow of refrigerant. They are located between the evaporator and condenser. 

Here are some types of expansion devices:
Thermostatic expansion valve (TXV): A precision device that regulates the flow of refrigerant into an evaporator. It reduces the pressure of the refrigerant liquid from the condenser and regulates the flow of refrigerant into the evaporator based on the temperature of the refrigerant at the evaporator outlet. TXVs also prevent excess liquid refrigerant from returning to the compressor.
Capillary tube: A long, wound-up copper tube with a tiny opening that receives hot, high-pressure liquid refrigerant from the condenser. The small opening holds high pressure on one side of the tube and low pressure on the opposite side.
Electronic expansion valve (EEV): Controls the amount of refrigerant that flows into an evaporator. EEVs are one of four main components in a refrigerant circuit. They prevent liquid refrigerant from entering the compressor, which can protect the compressor and improve demand control.
Orifice: A type of expansion device commonly used in residential air conditioning systems. It works by restricting the flow of refrigerant as it passes through.
Float valve: Actuated by a float that is immersed in the liquid refrigerant. Both low-side float and high side-float are used to control the flow of liquid refrigerant. 

Other types of expansion devices include:
Fixed orifice device
Manual valves
Automatic valves
Low-pressure float valves
High-pressure float valves