Category Archives for Controlling Refrigerant

HVAC Crankcase Pressure-Regulating Valves

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 normal shutdown period. When properly installed in the suction line, these valves automatically throttle … Continue reading

16. January 2011 by admin
Categories: Controlling Refrigerant | Tags: , | Leave a comment

HVAC Float valve

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 flow into the low side when a sufficient amount of refrigerant has been condensed to … Continue reading

16. January 2011 by admin
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HVAC Capillary tubing

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 a carefully measured length of very small diameter tubing. It creates a predetermined pressure drop … Continue reading

16. January 2011 by admin
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Thermostatic-expansion valve

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 to pressure from a remote bulb charged with a substance similar to the refrigerant in … Continue reading

16. January 2011 by admin
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Automatic-expansion valve

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 the valve opens, liquid refrigerant passes into the evaporator. The resulting increase in pressure in … Continue reading

16. January 2011 by admin
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Hand-expansion valve

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 is merely a needle valve with a fine adjustment stem. When the machine is shut … Continue reading

16. January 2011 by admin
Categories: Controlling Refrigerant | Tags: | Leave a comment

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