Spiral steel pipe production steps

Double-sided submerged arc welding straight seam steel pipe main process description

(1)Check the raw materials in various ways. Raw materials generally refer to the strip coil, welding wire, flux and so on. Before put into the strict physical and chemical inspection, in order to ensure the quality.

(2)The head and tail of the strip are butt-jointed, and single-wire or double-wire submerged arc welding is used, and automatic submerged arc welding is used to make up the welding after it is rolled into a steel pipe.

(3)Conduct process treatment. Before molding, the required steel is leveled, sheared and shaved, and the surface is cleaned and conveyed and the edges are bent.

(4)Adopt electric connection pressure gauge to control the pressure of the press-down cylinder on both sides of the conveyor, which ensures the smooth conveyance of the strip.

(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, the amount of misalignment and the weld gap are strictly controlled.

(7)Both internal and external welding are carried out by single-wire or double-wire submerged arc welding with American Lincoln electric welding machine, so as to obtain stable welding specifications.

(8)The welded seams are inspected by on-line continuous ultrasonic automatic scarifier, which ensures 100% NDT coverage of spiral steel pipes. If there are defects, automatic alarm and spray marking, according to which the production workers adjust the process parameters at any time to eliminate defects in time.

(9)Air plasma cutting machine is used to cut the steel pipe into single one.

(10)Cut into a single steel pipe, the first three of each batch of steel pipe to carry out a strict first inspection system, check the mechanical properties of the weld, chemical composition, dissolution status, surface quality of the steel pipe as well as non-destructive testing, to ensure that the pipe making process is qualified before officially put into production.

(11)The weld has continuous acoustic flaw marking parts, after manual ultrasonic and X-ray review, if there are defects, after repair, and again after nondestructive testing, until the defects are confirmed to have been eliminated.

(12)The pipe where the strip butt-welded weld and the butyl joint intersecting with the spiral weld are located, all of which are examined by X-ray TV or film.

(13)Each steel pipe is subjected to a hydrostatic pressure test with a radial seal pressure. The test pressure and time are strictly controlled by the microcomputer testing device for steel pipe hydrostatic pressure. The test parameters are automatically printed and recorded.

(14)The end of the pipe is mechanically processed, so that the verticality of the end face, bevel angle and blunt edges are accurately controlled.

Usually after these 14 steps, a spiral steel pipe has been shaped, but such a spiral steel pipe can not be sent directly to the market, but also need to carry out the quality of spiral steel pipe and other aspects of the inspection and so on. Introduction of LSAW steel pipe

LSAW steel pipe is a steel pipe with welded seams parallel to the longitudinal direction of the steel pipe. Usually divided into metric welded steel pipe, welded thin-walled pipe, transformer cooling oil pipe and so on.