Pressure control valves are widely used in water supply and drainage systems, fire protection systems and air conditioning systems.The pressure control valves of ZhengFeng mainly include the following: pressure reducing valve, pressure relief valve, pressure differential valve, water pump control valve and home pressure reducing valve. Pressure reducing valve adjusts and controls the outlet pressure of the main valve to enable the outlet pressure of the main valve not vary with inlet pressure, enable the outlet flow rate of the main valve not to vary with its outlet flow rate. Pressure relief valve is opened to prevent the pipeline and equipment from being damaged due to overpressure when the pressure in the water supply pipeline exceeds the set pressure of pressure relief. The valve closes automatically when pressure drops to the set value. Pressure differential valve can increase the utilization rate of the system, keep the pressure difference constant between the supply/return water pipelines, and minimize the noise of the system, as well as decrease the damage to the equipment caused by the excessive pressure difference. Pump control valve is installed at the outlet of the water pump. It can prevent the backflow of the medium, linked with the water pump, and can effectively prevent the water hammer phenomenon.