Category Archives for Controlling Refrigerant

ORO valve operation

The ORO head pressure-control valve is an outlet pressure–regulating valve that responds to changes in receiver pressure. The valve designation stands for opens on rise of outlet pressure (see Fig. 11-33). The inlet and outlet pressures are exerted on the … Continue reading

16. January 2011 by admin
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Head-Pressure Control Valves Operation

The ORI head pressure-control valve is an inlet pressure regulating valve. It responds to changes in condensing pressure only. The valve designation stands for opens on rise of inlet pressure. As shown in Fig. 11-32, the outlet pressure is exerted … Continue reading

16. January 2011 by admin
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Head-Pressure Control Valves

Design of air-conditioning and refrigeration systems using air-cooled condensing units involves two main problems that must be solved if the system is to be operated reliably and economically. These problems are high-ambient and low-ambient operation. If the condensing unit is … Continue reading

16. January 2011 by admin
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OBIT valve test and operating pressures

As with other pressure valves, it is possible to introduce nitrogen or carbon dioxide in an idle system to check for correct pressure settings. The usual precautions for working with gases apply here. The standard factory setting for the 0/50 … Continue reading

16. January 2011 by admin
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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
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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
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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
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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
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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
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