(1) Raw materials, i.e. strip coil, welding wire, flux. Before input are subject to strict physical and chemical inspection.
(2) Strip head and tail butt, using single or double wire submerged arc welding, and automatic submerged arc welding filler welding after rolled into steel pipe.
(3) Before forming, the strip is leveled, edge cutting, edge planing, surface cleaning and conveying and bending edge treatment.
(4) Adopt electric contact pressure gauge to control the pressure of the press down cylinder on both sides of the conveyor, which ensures the smooth transportation of the strip steel.
(5)Adopt external control or internal control roll forming.
(6) Weld gap control device is adopted to ensure that the weld gap meets the welding requirements, and the pipe diameter, misalignment amount and weld gap are strictly controlled.
Spiral steel pipe process
(7) Both internal and external welding are carried out by single or double wire submerged arc welding with American Lincoln welding machine, so as to obtain stable welding specification.
(8) The finished welds are inspected by online continuous ultrasonic automatic flaw meter, which ensures 100% nondestructive testing coverage of spiral welds. If there are defects, automatic alarm and spraying mark, production workers according to this at any time to adjust the process parameters to eliminate defects in a timely manner.
(9) Using air plasma cutting machine to cut the steel pipe into single pieces.
(10) cut into a single steel pipe, each batch of the first three steel pipe to carry out a strict * inspection system to check the mechanical properties of the weld, chemical composition, dissolution condition, the surface quality of the steel pipe and after non-destructive flaw detection inspection to ensure that the pipe production process qualified before officially put into production.
(11) welding seam with continuous acoustic flaw detection mark parts, after manual ultrasonic and X-ray review, such as defects, after repair, again after nondestructive testing until the confirmation of defects have been eliminated.
(12) strip butt weld seam and intersection with the spiral weld of the d-joint where the tube, all after X-ray television or film inspection.
(13) each steel pipe through the hydrostatic test, the pressure using radial seal. Test pressure and time are strictly controlled by the steel pipe water pressure microcomputer detection device. Test parameters are automatically printed and recorded.
(14) Pipe end mechanical processing, so that the verticality of the end face, bevel angle and blunt edge is accurately controlled.