(2) Influence of process conditions on weld formation
1) Influence of weld groove shape and clearance. When other conditions are the same, increasing the groove depth and width will increase the weld penetration, slightly reduce the weld penetration width, and significantly reduce the reinforcement.
2) Effect of flux stack height. The height of flux stack shall ensure that the arc is buried around the wire electrode, generally 25~40mm. When using bonding flux or sintered flux, the flux stack height is 20%~50% higher than that of melting flux from low dry density. The larger the flux stack height, the larger the weld reinforcement and the shallower the penetration.
3) The inclination angle of welding wire, welding nozzle and workpiece also has a greater impact on weld formation. During the welding of all welded pneumatic ball valves, the welding nozzle and welding wire shall be vertical to the surface of the dry workpiece as far as possible.

1. The performance of universal electromagnetic flowmeter in the accuracy class and function market is quite different. Some have high accuracy and multiple functions, while others have low accuracy and simple functions. The basic error of the instrument with high accuracy is (± 0.5% ～ ± 1%) R, and that of the instrument with low accuracy is (± 1.5% ～ ± 2.5%) FS. The price difference between the two is 1~2 times.