Sharing China-Made with Global Customers
Sharing China-Made with Global Customers
1. Material Inspection: Steel coils, welding wires, and fluxes are subjected to rigorous physical and chemical tests before use.
2. Welding Preparation: Steel strip ends are butt-welded using single or double wire submerged arc welding, followed by automated submerged arc welding repairs after forming the pipe.
3. Strip Conditioning: Includes leveling, edge trimming, planing, surface cleaning, and pre-bending of the steel strip.
4. Conveyor Pressure Control: Ensures smooth strip transport by controlling the pressure of the oil cylinders on both sides of the conveyor with electric contact pressure gauges.
5. Pipe Forming: Utilizes either external or internal roller forming techniques.
6. Weld Seam Management: Controls weld seam gaps to meet welding requirements, ensuring precise pipe diameter, misalignment, and gap.
7. Submerged Arc Welding: Uses American Lincoln machines for stable internal and external welds with single or double wire techniques.
8. Ultrasonic Testing: Continuous online ultrasonic inspection of weld seams guarantees 100% non-destructive testing coverage. Defects trigger alarms and markings, enabling immediate process adjustments.
9. Pipe Cutting: Air plasma cutting machines cut the pipes into specified lengths.
10. Batch Inspection: Every batch undergoes a comprehensive first inspection, checking weld seam mechanics, chemistry, fusion, surface quality, and non-destructive testing, ensuring qualification before production.
11. Defect Handling: Weld seams marked during ultrasonic testing are manually rechecked with ultrasonic and X-ray inspections. Confirmed defects are repaired and retested until eliminated.
12. Radiographic Inspection: Pipes with butt welds and intersecting spiral weld T-joints are inspected via X-ray TV or radiography.
13. Hydrostatic Testing: Each SSAW pipe undergoes a hydrostatic pressure test with radial sealing, controlled by a microcomputer device that records and prints test parameters.
14. End Finishing: Mechanical processing of pipe ends ensures precise control of end face perpendicularity, bevel angle, and blunt edges.