How is Spiral Welded Pipe manufactured?
Jindal spiral welded pipes (SWP) are made from a strip of low carbon structural steel or low alloy structural steel that is rolled into a tube blank at a specific spiral angle and then welded together. It’s possible to make it with a thinner strip. Steel is used to manufacture large-diameter steel pipes. Its specifications are specified as outer diameter * wall thickness, and the hydraulic test, weld tensile strength, and cold bending performance of the spiral welded pipes must all meet the criteria.
We have developed a comprehensive quality plan, on-site work procedures, and inspection and test programmes to ensure product quality.
The primary inspection/control items for spiral welded pipe adhering to the regulations of production standards are as follows:
- Length and appearance quality
- Chemical composition
- Tensile test of welded joint
- Hydrostatic pressure test
- Acid etching inspection
- Non-destructive inspection
To ensure the welding quality of the weld, the spiral welded pipe unit typically uses an online continuous inspection approach. Another element that distinguishes spiral welded pipe manufacturing from straight seam welded pipe manufacturing is this. Continuous inspection aids in the detection of welding flaws, the maintenance of welding quality, and the assurance of welding grade. The likelihood of welding concealed risks and quality issues may arise, as well as damage future pipeline operations’ overall functioning reliability.
SWP is a type of welded pipe as well. Its overall strength is greater than that of a straight seam welded pipe. It can make welded pipes with bigger pipe diameters from narrower blanks, as well as welded pipes. However, as compared to straight seam pipe, the length of the weld increases by 30-100%, as well as the manufacturing speed decreases. As a result, the majority of smaller diameter welded pipes use straight seam welding, while the majority of big diameter welded pipes use spiral welding for instance spiral welded Jindal pipes for oil, gas and water supply.
- Flux, welding wire, as well as Strip steel coils are the raw ingredients. Before investing, strict physical and chemical examinations are required.
- Single wire or double wire submerged arc welding connects the stripping head and tail, and automatic submerged arc welding is often used to repair the welding after coiling into a steel pipe.
- The strip is levelled, edge-trimmed, edge-planed, surface-cleaning and conveying, and pre-bending treatment before it is formed.
- To guarantee that the strip is transported smoothly, the electric contact pressure gauge is utilised to control the cylinders’ pressure over both sides of the conveyor.
- Roll forming with external or internal control is an option.
- The welding seam gap control device is used to ensure that the welding seam gap fulfils welding standards, and the pipe diameter, misalignment amount, and welding seam gap are all rigorously controlled.
- To achieve reliable welding requirements, both internal and external welding use the American Lincoln electric welding machine for single-wire or double-wire submerged arc welding.
- An online continuous ultrasonic automatic defect instrument inspects the welded seams after welding, ensuring 100% non-destructive testing coverage of spiral welds.
- Cut the steel pipe into individual pieces with air plasma cutting equipment.
- After being cut into single steel pipes, the first three of each batch must go through a rigorous first inspection system to check weld fusion status, chemical composition, surface quality, mechanical properties, as well as non-destructive inspections to ensure that the manufacturing process of the pipe is qualified as needed.
- Manual ultrasonic and X-ray examinations are performed on pieces having continuous sonic fault detection marks on the weld. If there are any problems, they will be inspected again after being repaired until the defects are confirmed.
- The end points of Jindal spiral welded coated pipes are machined to ensure that the end face’s verticality, bevel angle, and obtuse edge are all precisely controlled.
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