Pneumatic butterfly valve is composed of pneumatic actuator and butterfly valve. The pneumatic butterfly valve uses a round butterfly plate that rotates with the valve stem for opening and closing, so as to realize the starting action. The pneumatic valve is mainly used as a block valve. It can also be designed to have the function of regulating or section valve and regulating. At present, butterfly valves are increasingly used in low-pressure large and medium-sized pipelines.

What to pay attention to when welding pneumatic butterfly valve
Welding of bellows and joints
(1) Clean. Clean the joint and straight wall section of bellows with acetone
(2) Clamping. Assemble the joint and bellows according to the drawing, install the welding fixture, and then install it on the automatic welding installation.
(3) Welding. Adjust the welding current, welding speed, hydrogen flow and other parameters according to the process requirements, adjust the welding gun in place, test run and check whether the rotating installation can run smoothly. Finally, start welding according to the operation procedure of the automatic circumferential welding machine.
(4) Inspection. After the welding of the joints at both ends of the pneumatic butterfly valve is completed, the appearance inspection and air tightness inspection shall be stopped. The mesh sleeve shall be welded after passing the inspection.