Before being put into operation, it has to undergo severe physical and chemical examination. The head and tail of the strip is butt-joined, and single or double wire submerged arc welding is selected, and automatic submerged arc welding is selected to fill in the rolled steel pipe. Before forming, the strip is leveled, sheared and planed, and the surface is cleaned up for transport and bent edge treatment. Electric contact pressure gauge is selected to control the pressure of the press down cylinder at both ends of the conveyor to ensure the smooth transportation of the strip steel. Optional external control or internal control roll forming.
 
    Weld seam clearance control equipment is used to ensure that the weld seam clearance meets the welding requirements, and the pipe diameter, misalignment and weld seam clearance are severely controlled. Both internal and external welding are performed with single or double wire submerged arc welding by American Lincoln welding machine to obtain stable welding quality. The welded seam is inspected by online continuous ultrasonic automatic flaw meter to ensure 100 percent nondestructive testing coverage of the spiral weld.
Spiral steel pipes are subjected to severe physical and chemical tests before being put into operation
 
    If there are defects, automatic alarm and spraying symbols, production workers according to this at any time to adjust the process parameters to eliminate defects in a timely manner. Air plasma cutting machine is selected to cut the steel pipe into a single. After cutting into a single steel pipe, each batch of steel pipe are subject to severe * inspection principle, check the mechanical properties of the weld, chemical composition, soluble condition, steel pipe surface quality and non-destructive testing, to ensure that the pipe production process qualified, only after the formal production.
 
    Weld seam with continuous acoustic flaw detection symbols on the part, after manual ultrasonic and X-ray review, such as defects, after repair, again after nondestructive testing, until the defects have been eliminated. Strip steel butt weld seam and the address pipe with spiral weld seam intersection of the d-joint, all after X-ray television or film inspection. Each steel pipe through the hydrostatic test, the pressure selected radial seal. Test pressure and time are severely controlled by the steel pipe water pressure microcomputer testing equipment. Test parameters are automatically printed and recorded.