Crankcase pressure-regulating valves are designed to prevent overloading of the compressor motor. They limit the crankcase pressure during and after a defrost cycle or after…
A float valve, either high-side or low-side, can serve as a metering device. The high-side float, located in the liquid line, allows the liquid to…
Small-bore capillary tubing is used as a metering device. It is used on everything from the household refrigerator to the heat pump. Essentially, it is…
The thermostatic-expansion valve, used primarily in commercial refrigeration and air-conditioning, is a refinement of the automatic-expansion valve (see Fig. 11-3). A bellows or diaphragm responds…
The automatic-expansion valve controls liquid flow by responding to the suction pressure of the unit acting on its diaphragm or bellows (see Fig. 11-2). When…
Of the several types of metering devices. the hand-expansion valve is the simplest (see Fig. 11-1). Used only on manually controlled installations, the hand-expansion valve…
usually found at the top of the regulator. In an electrically compensated regulator, turning the stem to obtain different refrigerant pressures and temperatures in the…
A standard regulator is reset by manually turning the adjusting stem, which increases the spring pressure on top of the diaphragm. In an air compensated…
The upper portion of the valve head is similar to a standard pressure regulating head. On the lower portion of the head another diaphragm is…
In a refrigeration system designed to maintain a predetermined temperature at full load, any decrease in load would tend to lower below fullload temperature the…