The Z641H pneumatic flanged gate valve primarily consists of a flanged cast steel gate valve combined with a pneumatic actuator. It is an automated control valve driven by compressed air from the actuator, offering both air-to-open and air-to-close operation modes. This pneumatic flanged gate valve can be equipped with either electric or pneumatic position indicators to transmit valve status information, enabling remote control, centralized control, and automated control. The flanged pneumatic cast steel gate valve employs a dual-cylinder structure with a buffer mechanism. Compared to single-cylinder pneumatic gate valves, its lifting force is doubled. This effectively reduces the impact shock during piston descent when closing the valve, minimizing wear on the gate disc seal face and valve body seal face. It also prevents gate disc jamming.