The selection of welding wire material is mainly based on the valve body material. For common valve body materials, carbon steel welding wire such as H08MnA and low alloy steel welding wire such as H10Mn2 are usually selected as welding wire materials. At the same time, the selection of welding wire diameter also has a great impact on the weld shape. When the welding current, arc voltage and welding speed are fixed, the weld penetration is inversely proportional to the welding wire diameter, and the weld width is proportional to the welding wire diameter. For the submerged arc automatic welding commonly used for all welded pneumatic ball valves, the welding wire diameter is generally 2.5~6mm.

Selection of rotary compensator and sleeve compensator data
A series of maintenance shall be stopped before the rotary compensator leaves the factory. There are five main types:
1、 Working pressure, general scale is 1.6kg
2、 Maximum combined compensation 1800mm
3、 Device length 225/380mm
4、 Pressure test When the test pressure reaches 1.5 times of the working pressure, i.e. 2.4Mpa, and the pressure is maintained for 10 minutes, the product is free of leakage and structural damage.
5、 Burst pressure test
When the test pressure reaches 3 times of the working pressure, i.e. 4.8 Mpa, and the pressure is maintained for 10 minutes, the product is free of leakage and structural damage.