The raw material is the steel coil, the welding wire, the flux. must undergo rigorous physical and chemical examination before putting into operation. In the butt joint of strip, the single wire or double wire submerged arc welding is used, and the automatic submerged arc welding is used to weld the steel tube after winding.
Before forming, the steel strip passes through the leveling, the shearing edge, the planing edge, the surface cleans transports and bends the edge processing.
Using the electric contact pressure gauge to control the pressure of the oil cylinder on both sides of the conveyor to ensure smooth conveying of the strip.
The use of external control or internal control roll molding. The weld clearance control device is used to ensure the weld clearance meets the welding requirements, the diameter, the wrong edge and the weld gap are strictly controlled. Both internal and external welding using the American Lincoln Welding Machine for single wire or double wire submerged arc welding, so as to obtain a stable welding specifications. The weld has been inspected by an on-line continuous ultrasonic automatic wound tester to ensure the nondestructive testing coverage of 100% spiral welds.
Use air plasma cutting machine to cut the steel pipe into single root. Cut into a single steel pipe, each batch of steel pipe head three to carry out strict first inspection system, to ensure that the pipe process qualified, formally put into production.
There are continuous sonic flaw marks on the weld, after manual ultrasound and X-ray review. The tube of the steel butt weld and the butyl joint which intersects with the spiral weld, all through the X-ray television or the film. After hydrostatic test, the pressure is radial sealed. The test pressure and time are strictly controlled by the hydraulic micro-computer detecting device. The test parameter automatically prints the record. Pipe end machining, so that the end of the vertical, slope and blunt edge of the accurate control.
