WorksheetsUnit 24: Expansion Devices
Total questions: 10
Worksheet time: 5mins
Expansion Devices
Divide the high and low sides of the refrigeration system
Meter the correct amount of refrigerant to the evaporator
Installed in the liquid line at the inlet of the evaporator
all of the above
The following is not an example of an expansion device
Automatic expansion valve (AXV)
Thermostatic expansion valve (TXV)
Fixed bore (capillary tube)
Rotary expansion valve (RXV)
Why is superheat necessary in a TXV?
Superheat ensures that no liquid refrigerant leaves the evaporator.
Superheat makes the condenser compress refrigerant.
Superheat ensures that the refrigerant boils.
Superheat is not necessary in a TXV.
What are the components of a TXV
Sensing bulb and transmission tube
Diaphragm
Needle and Seat
Spring
All of the above
The valve body is made out of:
Aluminum
Brass or Stainless Steel
Copper
Iron
The Diaphragm
Moves the needle in and out of the seat in response to system load changes
Made of thin, flexible stainless steel
Located at the top of the valve
All of the above
The greater the pressure difference across the needle and seat, the _____________ the amount of flow through the valve.
lesser
greater
same
The pressure across the needle and seat does not affect the amount of flow through the valve.
_______________pressure determines the evaporator superheat; factory set to maintain between 8°F and 12°F of superheat in the evaporator.
Head
Air
Spring
Temperature
One side of the ______________ gets its pressure from the ________________, and the other side gets its pressure from the evaporator and the spring.
needle and seat
diaphragm and sensing bulb
temperature and pressure
metering device and compressor
The __________________________________ Controls refrigerant flow by the pressure drop across it
RXV Metering Device
AXV Metering Device
TXV Metering Device
CapillaryTube Metering Device
