Discharge-Bypass Valves

Many of the air conditioning and refrigeration systems it is desirable to limit the minimum pressure boil. It is, especially in periods of low demand, to prevent coil to avoid icing or operation of the compressor suction pressure lower than it was designed for. Various working methods were developed to achieve the integral handling of cylinders, gas engines with variable speed or several smaller systems. Compressor discharge widely used on large systems. However, it's too expensive, small equipment, as a rule, 10 HP or below. Cycling low-pressure compressor, cut management is widespread, but overpriced for three reasons:

On-off control of the air-conditioning systems uncomfortable and ill humidity control.
Compressor reduces the life of the equipment.
In most cases, the compressor is economically inexpedient, since the peak load charges.

One solution to the problem is to bypass part of the hot gas discharge directly into the bottom side. This is done by regulating valve adjustment, usually called discharge bypass valve (DBV). This is a valve that opens on the lower intake pressure may be installed automatically to keep the necessary minimum of evaporating pressure, regardless of reducing the load on the evaporator.