Hot gas by-pass valves
Where the compressor does not have any compromising product performance and off will not give the degree of control necessary in the process of cooling capacity can be regulated through the introduction of gas flow back into the reception (see Fig. 9.2). This has the effect of maintaining constant pressure in the evaporator, regardless of load, and can have a wide range reduction, productivity up to 10% of the full load. This constant pressure valve, balancing the suction pressure against preset spring.
They can be either direct or pilot operated. They are often equipped with external equalizer, which works as well as externally equalized the expansion valve. The use of hot gas upstream of the evaporator gives the possibility of the expansion valve to open and admit more cool refrigerant, which supports the speed of the gas in the evaporator and AIDS oil return.
Please note solenoid valve Fig. 9.2. If the system is configured with the help of pump down is solenoid valve must be connected in parallel with the electromagnetic pump to reach the pump down. This method manage energy....
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Controls and Other Circuit Components