What is the manufacturing process of spiral welded pipe?

Spiral welded pipe manufacturing process

(1) The raw materials are strip coil, welding wire and flux. Before input, it must undergo strict physical and chemical tests.

(2) Strip steel head and tail butt joint, using single wire or double wire submerged arc welding, after coiled into steel pipe, automatic submerged arc welding repair welding.

(3) Before forming, the strip steel is leveled, trimmed, planed, surface cleaned and conveyed and pre-bent.

(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 transportation of the steel strip.

(5) Use external control or internal control roll forming.

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

(7) Both internal and external welding adopt American Lincoln electric welding machine for single-wire or double-wire submerged arc welding, so as to obtain stable welding quality.

(8) The welded seams are all inspected by online continuous ultrasonic automatic flaw detector to ensure the coverage of non-destructive testing of spiral welds. If there are defects, it will automatically alarm and spray marks, and the production workers will adjust the process parameters at any time according to this, and eliminate the defects in time.

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

(10) After cutting into a single steel pipe, each batch of steel pipes must undergo a strict first inspection system to check the mechanical properties, chemical composition, fusion state, surface quality of the steel pipe and non-destructive inspection to ensure that the pipe making process is qualified Only then can it be officially put into production.

(11) The parts with continuous sonic flaw detection marks on the welding seam are reviewed by manual ultrasound and X-ray. If there are defects, after repairing, they will undergo non-destructive inspection again until it is confirmed that the defects have been eliminated.

(12) The tubes where the butt-welded welds of steel strips and the D-shaped joints that intersect with the spiral welds have all been inspected by X-ray TV or filming.

(13) Each steel pipe has undergone hydrostatic pressure test, and the pressure is radially sealed. The test pressure and time are strictly controlled by the steel pipe hydraulic microcomputer detection device. Test parameters are automatically printed and recorded.

(14) Mechanical processing of the pipe end, so that the verticality of the end face, the bevel angle and the blunt edge are accurately controlled.