Metering Devices Highlights Flashcards
Cap tube min internal diameter?
0.028
Cap tube maximum ID
0.095
Cap tube min length?
6’
Cap tube max length?
18’
Actuator is a carrier term for orifices?
Yes
Orifice and cap tube low starting torque?
Yes
How are hand expansion valves adjusted?
By hand dummy
Are hand expansion valves for DX coils or flooded?
Flooded
What kind of load is an aev best for?
Constant
What size if machinery are aevs seen in?
Small, like a slurpee
Do aevs Overfeed under load and starve under load?
Yes
Does an AEV equalize when off?
Yes
Low side float evaporator is?
Flooded
Txv capacity increases with an increase in pressure drop
Yes
Txv formula=
P1=P2+P3
P1=
Bulb
P2=
Evaporator pressure
Type CP=
Air conditioning
Type C=
Refrigeration
50 to -10F
Type Z=
Low temp
0 to -40F
Type X=
Xtra low
-40 to -100F
Type N=
Adsorption
Does adsorption have a built in MOP
No
Where is a hydraulic element used
Chillers
What temp sensor does an EEV use
A thermistor
Air conditioning temp range/super heat
40-50F
Superheat 8-12F
Refrigeration temp range/superheat
0-40F
Superheat 6-8F
Low temp temp range/superheat
0 to -40F
Superheat 4-6F
Mop???
Maximum operating pressure
Mop protects what?
The compressor
Ammonia TXV body material?
Steel body
Thermal electric expansion valve, hoe does it open
Heat and a bimetal strip
Thermal electric expansion valve uses bulb or thermistor???
A thermistor
