1. Receipt of material
Before being taken in for pipe production the sheet and plate base material is inspected to ensure that it conforms with relevant specifications.
Inspection: Checking of mill certificate. Random checking of dimensions and surface finish.

2. Marking
One end of the sheet/plate is punched with a serial number, which helps identify the pipe at all stages throughout production.

3. Edge preparation
The edges are prepared to suit the appropriate welding method.

4. Forming
The sheet/plate is formed to tubular shape.

5. Welding
Depending upon pipe size and specifications, the pipe is welded using one of the following methods or a combination thereof:

• PAW, Plasma Arc Welding
• TIG, Tungsten Inert Gas of Gas Tungsten Arc Welding
• SAW, Submerged Arc Welding

Inspection: Carried out at random. Visual inspection.

6. Grinding
The outside weld bead can be removed by a grinding operation.

7. Heat treatment
The pipe is normally quench annealed after welding.
Inspection: Control and recording of furnace temperature and pipe velocity through the furnace.

8. Pickling
It is vital that the pipe is completely free of scale. A unique shotblasting operation before the pickling and passivation processes ensures an efficient and uniform action by the pickling acid, resulting in a smooth surface finish and maximum corrosion resistance.
Inspection: Daily check of pickling acid concentration.

9. Straightening
Manual operation for adjustment to required straightness.

10. Sizing
The pipe is calibrated to specified outside diameter and roundness.

11. Cutting
Before cutting to length, the pipe identification number is re-marked on the pipe. In conjunction with the cutting operation, all specimens for the mechanical tests are taken according to specifications and standards.
Inspection: Mechanical tests.

12. Hydrostatic testing
The pipe is hydrostatically tested according to specification requirements.
Inspection: Test pressure recorded.

13. Non-Destructive Testing
A robot operated X-ray line ensures a quick and reliable testing operation with automatic identification of the pipe number on the film.
Inspection: X-ray according to specification.

14. End machining
Both ends are machined according to specification.

15. Final inspection
Visual inspection and dimensional control.

16. Marking and packaging
Relevant marking is applied along the entire pipe.

17. Dispatch of pipe
The pipe is dispatched only when the results of all specified testing and inspection operations have been approved by the QC Department. 

Dimension range - Pipes welded from plates