(4) If the on-off butterfly valve is used outdoors, the protection of the valve rod shall be strengthened to prevent corrosion in rainy and snowy days. 　　

Pneumatic ball valve is a ball valve equipped with a pneumatic actuator to drive the opening and closing of the ball valve through the pneumatic actuator. Because the pneumatic actuator is relatively fast in implementation, and the fast opening and closing speed is 0.05 seconds/time, it is also commonly called pneumatic quick stop ball valve. Generally, pneumatic ball valves are not used alone. They are usually equipped with various accessories, such as solenoid valves, air source processing triplets, limit switches, positioners, control boxes, etc., which are intended for local control and remote centralized control. The valve can be opened and closed in the control room without the need to go to the site or to the high altitude and dangerous areas for manual control, It saves human resources, time and security to a large extent.