Monthly Archives for January 2011

Evaporator Pressure-Regulating Valves Location

ORITs must be installed upstream of any other suction-line controls or accessories. These valves may be installed in the position most suited to the application. However, these valves should be located so that they do not act as an oil … Continue reading

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

Evaporator Pressure-Regulating Valves Operation

For any pressure sensitive valve to modulate to a more closed or open position, a change in operating pressure is required. The unit change in the valve stroke for a given change in the operating pressure is called the valve … Continue reading

16. January 2011 by admin
Categories: Controlling Refrigerant | Tags: , | 1 comment

Evaporator Pressure-Regulating Valves

Evaporator pressure-regulating valves offer an efficient means of balancing the system capacity and the load requirements during periods of low loads. They are also able to maintain different evaporator conditions on multi temperature systems. The main function of this valve … Continue reading

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

HVAC CRO Valve Service

Since CRO valves are hermetic and cannot be disassembled for inspection and cleaning, they are usually replaced if inoperative. If a CRO fails to open, close properly, or will not adjust, solder or other foreign material is probably lodged in … Continue reading

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

HVAC CRO Valve Adjusting the pressure

The standard setting by the factory for CROs in the 0/60 psig range is 30 psig. Since these valves are adjustable, the setting may be altered to suit the specific system requirements. CROs should be adjusted at startup when the … Continue reading

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

HVAC Crankcase Pressure-Regulating Valves Location

As Fig. 11-27 indicates, the CRO valve is applied in the suction line between the evaporator and the compressor. Normally, the CRO is installed downstream of any other controls or accessories. However, on some applications it may be advisable or … Continue reading

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

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
Categories: Controlling Refrigerant | Tags: | Leave a comment

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
Categories: Controlling Refrigerant | Tags: | Leave a comment

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
Categories: Controlling Refrigerant | Tags: , | Leave a comment

← Older posts

Newer posts →