Spiral steel pipe production process: It is a spiral seam steel pipe welded by automatic double-wire double-sided submerged arc welding process using strip steel coil plate as raw material, constant temperature extrusion molding.
(1) Raw materials, namely strip coils, welding wires, and flux, must undergo strict physical and chemical inspections before being put into use.
(2) The head and tail of the steel strip are butt-jointed using single-wire or double-wire submerged arc welding. After being rolled into a steel pipe, automatic submerged arc welding is used for repair welding.
(3) Before forming, the strip steel is leveled, trimmed, planed, surface cleaned, transported, and pre-bent.
(4) Electric contact pressure gauges are used to control the pressure of the cylinders on both sides of the conveyor, ensuring smooth transportation of the strip.
(5) Adopt 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. The pipe diameter, offset amount, and weld gap are strictly controlled.
(7) Both internal and external welding use American Lincoln welding machines for single-wire or double-wire submerged arc welding to obtain stable welding specifications.
(8) All welded seams have been inspected by an online continuous ultrasonic automatic flaw detector to ensure 100% non-destructive testing coverage of the spiral welds. If there are defects, an automatic alarm will be issued and markings will be sprayed on. The production workers can adjust the process parameters at any time accordingly. Eliminate defects promptly
(9) Use an air plasma cutting machine to cut the steel pipe into individual pieces.
(10) After cutting into individual steel pipes, the first three steel pipes in each batch must undergo a strict first inspection system to check the mechanical properties, chemical composition, fusion status of the welds, the surface quality of the steel pipes, and non-destructive testing to ensure the pipe making process Only after passing the test can it be officially put into production.
(11) The parts with continuous sonic flaw detection marks on the welds have been reviewed by manual ultrasonic and
(12) The pipes where the strip butt welds and the T-shaped joints that intersect the spiral welds are located have all been inspected by X-ray television or films.
(13) Each steel pipe has undergone a hydrostatic test. The pressure adopts a radial seal test. The pressure and time are strictly controlled by the steel pipe water pressure microcomputer detection device and the test parameters are automatically printed and recorded.
(14) The pipe end is mechanically processed to accurately control the verticality, bevel angle, and blunt edge of the end face. Features of spiral steel pipes: The production process of straight seam welded pipes is simple, the production efficiency is high, the cost is low, and the strength of spiral welded pipes is generally higher than that of straight welded pipes. Seam-welded pipes are taller and can use narrower billets to produce welded pipes with larger diameters. Welded pipes with different diameters can also be produced from billets of the same width. However, compared with straight seam pipes of the same length, the weld length is increased by 30~100%. , and the production speed is low. Therefore, smaller-diameter welded pipes mostly use straight seam welding, while large diameter welded pipes mostly use spiral welding.
Spiral pipes and their standard classifications: Spiral seam submerged arc welded steel pipes for pressure-bearing fluid transportation (SY5036-83) are mainly used for pipelines transporting oil and natural gas; spiral seam high-frequency welded steel pipes for pressure-bearing fluid transportation (SY5038-83), The spiral seam high-frequency welded steel pipes used for pressure-bearing fluid transportation are welded by high-frequency lap welding. The steel pipes have strong pressure-bearing capacity, and good plasticity, and are easy to weld and process. Generally, spiral seam submerged arc welded steel pipes are used for low-pressure fluid transportation ( SY5037-83), a submerged arc welded steel pipe made by double-sided automatic submerged arc welding or single-sided welding for general low-pressure fluid transportation such as water, gas, air, and steam.
Nowadays, the commonly used standards for spiral steel pipes are generally divided into: SY/T5037-2000 (ministerial standard, also called spiral submerged arc welded steel pipe for ordinary fluid transportation pipelines), GB/T9711.1-1997 (national standard, also called oil and gas industry transportation Steel pipe delivery technical conditions Part 1: Grade A steel pipe), API-5L (American Petroleum Institute, also called pipeline steel pipe), SY/T5040-92 (spiral seam submerged arc welded steel pipe for piles)
Spiral pipe material: Q235A, Q23b, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb. Q345 L245 L290 X42 X46 X70 X80
Spiral welded steel pipe Spiral welded steel pipe refers to a steel pipe that is made by bending and deforming a steel strip or steel plate into a round, square, etc. shape and then welding it. The steel pipe has seams on the surface. According to different welding methods, it can be divided into arc welded pipe, high-frequency, or low-frequency resistance welded pipe, gas welded pipes, furnace welded pipes, Bondi pipes, etc. can be divided into straight seam welded pipes, and spiral welded pipes according to the shape of the weld. Electrically welded steel pipes are used in oil drilling and machinery manufacturing. Furnace welded pipes can be used as water and gas pipes. Large diameter straight seam welded pipes are used. For high-pressure oil and gas transportation, etc.; spiral welded pipes are used for oil and gas transportation, pipe piles, bridge piers, etc. Welded steel pipes have lower costs and higher production efficiency than seamless steel pipes. The production process of straight seam welded pipes is simple, with high production efficiency, and low cost, and the development of spiral welded pipes is rapid. The strength is generally higher than that of straight seam welded pipes. Welded pipes with larger diameters can be produced from narrower billets. Welded pipes with different diameters can also be produced from billets of the same width. However, compared with straight seam pipes of the same length, the weld length is increased. 30~100% and the production speed is low. Therefore, smaller-diameter welded pipes mostly use straight seam welding, while large diameter welded pipes mostly use spiral welding.
Post time: Jan-23-2024