The ZZY self-pressure regulating valve operates without external energy, utilizing the energy of the medium being adjusted as the power source to control the valve core position through the actuator, thereby modifying the pressure difference and flow at both ends, ensuring stable pressure before (or after) the valve. It boasts advantages such as sensitive operation, good sealing, and minimal fluctuation in the pressure setting point. It is widely used in automatic control for减压稳压 or 泄压稳压 of gases, liquids, and steam media. This series includes three structures: single seat (ZZYP), sleeve (ZZYM), and double (ZZYN); the actuators come in two types: diaphragm and piston; and the operating types include pressure reduction with post-valve pressure regulation (Type B) and pressure relief with pre-valve pressure regulation (Type K). The nominal pressure classes are PN16, 40, and 64; the valve body bore range is DN20 to 300; the leakage quantity grades are II, IV, and VI; the flow characteristic is quick opening; and the pressure step adjustment ranges from 15 to 2500Kpa. It can be customized to meet the user's operating conditions as required.