This series of pressure reducing valve belongs to the guide piston type pressure reducing valve.Consists of two parts, the main valve and pilot valve.The main valve is mainly composed of valve seat, the main valve, piston, spring and other parts.Pilot valve is mainly composed of the seat, disc, diaphragm, spring, adjusting spring and other parts.By adjusting the adjusting the spring pressure setting outlet pressure, the use of diaphragm sensing outlet pressure changes, through the pilot valve opening and closing drive piston to adjust the size of the main valve throttle position over-current, realize the function of reduced pressure regulator.