The PQ640H pneumatic eccentric half-ball valve features frictionless operation, wear-resistant sealing, and low opening/closing torque. It controls pipeline media by rotating a half-spherical body around an eccentric axis. During operation, no friction occurs between the ball and the valve seat sealing surface, minimizing seal wear and significantly extending service life. Given that the structural principle of the pneumatic eccentric half-ball valve closely resembles the operational mechanism of a triple-offset butterfly valve, some refer to the eccentric half-ball valve as a butterfly valve with a spherical disc.