Restrictor Valves and Expansion Valves in Air Conditioners

Guess it all rests on the basic formula P1V1/t1 = P2V2/T2.

It just depends what you want to do as all remains equal during the process ingnoring losses to insulation.

just off the top of my head.......

a restrictor is a fixed orifice in the evaporator inlet.

an expansion valve is a variable valve used to control pressure/temperature in the system, usually with some means to adjust when used in commercial refrigeration. when used in automotive applications no adjustment is available.

Hi !

Restrictor is just very small opening (orifice or just very small tubing). It can not maintain constant superheat or pressure. Cheapest a/c use this type of metering devices.

Expansion valve (TXV) is valve that can maintain constant superheat. It means it opens up more when evaporator needs more freon. You can find them in better systems.

Most sophisticated is electronic expansion valve - it has a step motor and is electronically controlled. You can find them in ductless systems (not in all of them) or other special applications.

please some one explain about the working of EXPANSION VALVE or an EXPANSION DEVICE.. how does the high pressure, high temperature liquid refrigerant turns into low pressure low temperature liquid..?