The 77/78-36100 pneumatic O-ring cut-off ball valve consists of two parts: pneumatic single and double acting actuators and an O-ring ball valve. DN15-DN200 ball valves have a floating ball structure and are equipped with flexible lip shaped valve seats, while DN250 and DN300 ball valves have a fixed ball structure. The actuator adopts imported gear and rack type dual piston pneumatic actuators, which have two structural forms: single acting and double acting. The pneumatic O-ring cut-off ball valve has the advantages of simple structure, small volume, light weight, reliable sealing, long service life, and easy operation. It can be widely used in automation and remote control of industries such as petroleum, chemical, power, food, and textile.