ZZY type self-operated pressure regulating valve does not need additional energy, uses the self-energy of the regulated medium as the power source, introduces the actuator to control the position of the spool, changes the pressure difference and flow at both ends, and stabilizes the pressure before (or after the valve). It has the advantages of sensitive action, good sealing and small fluctuation of pressure set point, and is widely used in the automatic control of pressure reduction and regulation or pressure relief and regulation of gas, liquid and steam media. The function types of this series of regulating valves include pressure adjustment after pressure reduction (type B) and pressure adjustment at the front for pressure relief (type K). Pressure segmentation adjustment from 15~250KPa. It can be combined according to the needs to meet the requirements of user working conditions.