The ZZY type self-pressure regulating valve operates without external energy, utilizing the energy of the medium being adjusted as the power source to drive the actuator and control the valve core position. It modifies the pressure difference and flow at both ends, stabilizing the pressure before (or after) the valve. It boasts advantages such as sensitive operation, good sealing, and minimal pressure setting point fluctuation. It is widely used in automatic control for reducing and stabilizing pressure or releasing and stabilizing pressure in gases, liquids, and steam. This series includes three structures: single seat (ZZYP), sleeve (ZZYM), and double (ZZYN); two types of actuators: diaphragm and piston; and two types of functions: pressure reduction valve after (B type) and pressure release valve before (K type). The nominal pressure classes are PN16, 40, and 64; the valve body bore range is DN20 to 300; the leakage rate grades are II, IV, and VI; the flow characteristic is quick opening; and the pressure regulation is from 15 to 2500 Kpa. It can be customized to meet the user's operating conditions.