(2) Flux material selection Flux plays the role of isolating air, protecting weld metal from air immersion and participating in the metallurgical reaction of molten pool metal in the welding process. When the welding wire is determined, the matching flux becomes the key material, which directly affects the mechanical properties (especially plasticity and low-temperature toughness), crack resistance, occurrence rate of welding defects and welding productivity of the weld metal.

Pneumatic ball valve is a complete set of valves composed of high platform ball valve and pneumatic actuator. The pneumatic ball valve is equipped with a pneumatic actuator. The execution speed of pneumatic actuator is relatively fast, and the fastest switching speed is 0.05 seconds/time, so it is usually also called pneumatic quick cut-off ball valve.