Is it necessary to install a bypass and control valve for screw compressors?

Control methods for regulating the flow rate of screw compressors: 1. By adjusting the speed: Since a screw compressor is a positive-displacement machine, the best way to regulate its flow rate is by changing its rotational speed. This can be solved through the following methods: using speed-regulated motors, frequency converters, or turbine drives. The lowest speed that a compressor can achieve is roughly 50% of its maximum allowable speed. Second, bypass regulation: A bypass system is used, allowing excess gas to return to the inlet through a control valve, thereby ensuring the pressure required by the system. The bypass gas is cooled to the intake air temperature by a cooler ； III. Full/empty load system adjustment: When the system reaches the preset pressure, the pressure switch activates, and the diaphragm valve opens a bypass between the compressor’s inlet and outlet. The compressor then starts to run under no-load conditions until the system pressure drops to the preset minimum allowable pressure. When the diaphragm valve is closed again in response to the pulse signal sent by the pressure switch, the compressor operates at full load as normal ； IV. Inlet throttling control: This method is applicable to compressors only in conjunction with the full-load/empty-load system control. When a full/load/unload control system is used, the compressor discharges directly once the system pressure reaches the preset maximum value. Meanwhile, the suction side of the compressor system is reduced to 0.15 bar (absolute pressure) through a throttle valve. When the system pressure drops to the preset minimum allowable pressure, the compressor resumes normal full-load operation. From the above adjustment methods, it can be seen that screw compressors can be equipped with bypasses.