(1) Raw materials, namely strip coil, welding wire, flux. Strict physical and chemical tests should be carried out before investment.

(2) Single or double wire submerged arc welding is used for butt butt of strip steel, and automatic submerged arc welding is used for repair welding after rolling steel pipe.

(3) before forming, strip after leveling, cutting, planing, surface cleaning, transportation and bending processing.

(4) The electric contact pressure gauge is used to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth delivery of strip steel.

(5) using external control or internal control roller forming.

(6) The weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, staggered edge and weld gap are strictly controlled.

(7) Single wire or double wire submerged arc welding is performed by American Lincoln welding machine for both internal and external welding, so as to obtain stable welding specifications.

(8) All welded welds are inspected by on-line continuous ultrasonic automatic damage tester to ensure 100% nondestructive testing coverage of spiral welds. If there are defects, automatic alarm and spray marking, production workers according to the adjustment of process parameters, timely elimination of defects.

(9) Use air plasma cutting machine to cut the steel pipe into a single root.

(10) After cutting into a single steel pipe, each batch of steel pipe should carry out a strict first inspection system to check the mechanical properties of the weld, chemical composition, melting condition, surface quality of the steel pipe and after nondestructive testing to ensure that the pipe making process is qualified, before it can be formally put into production.

(11) The part with continuous acoustic detection mark on the weld, after manual ultrasonic and X-ray review, if there is a defect, after repair, again through non-destructive testing, until it is confirmed that the defect has been eliminated.

(12) The pipe where the butt weld of strip steel and the t-joint intersecting the spiral weld are all inspected by X-ray TELEVISION or film.

(13) Each steel pipe is hydrostatic tested and the pressure is radial sealed. The test pressure and time are strictly controlled by the microcomputer testing device for water pressure of steel pipe. Automatic printing and recording of test parameters.

(14) The tube end is machined to accurately control the verticality of the end face, groove Angle and blunt edge.