Spiral Steel pipe is the production process of the raw material with strip coil

Spiral steel pipe is a steel coil plate as raw material, often warm extrusion molding, automatic double-wire double-sided submerged arc welding process into the spiral seam pipe. 

(1) raw material namely strip coil, welding wire, flux.Before the input must undergo rigorous physical and chemical tests.

(2) Steel head and tail docking, the use of single wire or double wire submerged arc welding, after the coil into the steel pipe with automatic submerged arc welding repair.

(3) before forming, the strip has been leveling, trimming, trimming, surface cleaning and conveying and bending edge treatment.

(4) Use the electric contact pressure gauge to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth conveying of the strip.

(5) Using external control or internal control roll molding.

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

(7) Internal welding and external welding are used in the United States Lincoln Welding machine for single or double wire submerged arc welding, so as to obtain a stable welding quality. 

(8) The welded welds are inspected by the on-line continuous ultrasonic automatic injury instrument, which guarantees the NDT coverage of 100% of the spiral welds.If there are defects, automatic alarm and spraying mark, the production workers adjust the process parameters at any time, eliminate defects in time.

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

(10) cut into a single pipe, each batch of steel pipe must carry out a strict first inspection system, inspection of the mechanical properties of the weld, chemical composition, fusion status, the quality of steel pipe and through nondestructive testing, to ensure that the pipe process qualified to be formally put into production.

(11) The Weld has a continuous sonic flaw mark on the site, after manual ultrasound and X-ray review, if there is a defect, after repair, again through non-destructive testing, until the identification of the defect has been eliminated.

(12) The tube of the steel butt weld and the ding-type joint which intersect with the spiral weld are inspected by X-ray television or film. (13) Each steel tube after hydrostatic test, pressure using radial seal. The test pressure and time are strictly controlled by the steel tube hydraulic pressure microcomputer detecting device.

Test parameters automatically print records. (14) Pipe end machining, so that the end of the vertical, slope and blunt edge of the angle is accurately controlled.