The ZSH(DR)Z series eccentric rotary valve consists of a pneumatic piston or electric actuator and an eccentric rotary valve body. It is a quarter-turn control valve in which a partial ball segment rotates around an eccentric axis to regulate flow. The unique eccentric relationship between the ball segment and sealing ring provides a compact structure, good shutoff performance and long service life, combining both throttling and shutoff functions. Metal-seated versions meet leakage Classes IV and V, while soft-seated versions meet Class VI and can achieve zero leakage; the flow characteristic is approximately linear.