What’s the process flow of spiral welded steel pipes?

Workers produce spiral welded steel pipes using an automated double-wire double-sided submerged arc welding process, using strip steel or coiled plate as raw materials for constant temperature extrusion molding.

Here’s a brief overview of the manufacturing process:

1. Raw Material Preparation: Steel strip coil, welding wire, and flux undergo rigorous physical and chemical inspections before use.
2. Welding Process: Butt joints connect the head and tail of the steel strip using single-wire or double-wire submerged arc welding. After rolling into a steel pipe, workers use automatic submerged arc welding for repair welding.
3. Pre-Forming: Strip steel is leveled, trimmed,planed, surface cleaned, transported, and pre-bent.
4. Forming: Electric contact pressure gauges ensure smooth strip conveying, while external or internal control roller forming shapes the pipe.
5. Weld Gap Control: Devices regulate the weld gap, ensuring strict parameters for pipe diameter, offset amount, and weld gap.
6. Welding: American Lincoln electric welding machines perform single-wire or double-wire submerged arc welding to achieve stable welding quality.
7. Inspection: Completed welds undergo online continuous ultrasonic automatic flaw detection to ensure 100% non-destructive testing coverage.
8. Cutting: An air plasma cutting machine precisely cuts the steel pipe into individual pieces.
9. First Inspection: Each batch of steel pipes undergoes a strict first inspection system to check mechanical properties, chemical composition, weld fusion status, surface quality, and non-destructive testing.
10. Defect Correction: Areas with continuous sonic flaw detection marks undergo manual ultrasonic and X-ray re-examination for defect correction.
11. Butt Weld and T-Joint Inspection: Workers inspect butt welds and T-joint intersections with spiral welds using X-ray television or film.
12. Hydrostatic Pressure Test: Each steel pipe undergoes a hydrostatic pressure test with strict control over pressure and time, ensuring radial sealing.
13. End Machining: Workers machine pipe ends to control end face verticality, bevel angle, and blunt edge.

Manufacturer’s Challenge

Despite economic challenges, the spiral welded steel pipe industry is recovering, with a promising future in gas transportation and distribution.

Cangzhou DoubleDragon Steel Pipe Co., Ltd specializes in producing spiral welded steel pipes. With 30 years of experience, we offer diameters from 8 to 140 inches and wall thicknesses from 6 to 26mm. Friends worldwide are welcome to exchange and consult.