Manufacturing Process of Seamless Pipes & Tubes

1

Round billets

Round steel billets are prepared as the primary raw material for seamless tube production. The billets are selected according to the required steel grade, size, and quality specifications.

2

Recheck

The billets are rechecked for dimensions, surface condition, identification, and material quality before entering the production line.

3

Skinning

The billet surface is skinned to remove superficial defects and impurities, providing a cleaner and more uniform surface for subsequent processing.

4

Banking

The billet is cut or blanked into sections of the required length to ensure stable and consistent processing in the following operations.

5

Centering

The billet end is accurately centered to establish the correct starting point for piercing and improve dimensional accuracy during tube formation.

6

Heating

The billet is uniformly heated to the specified processing temperature to achieve suitable plasticity for hot piercing and forming.

7

Perforation

The heated billet is pierced to create an initial hollow shell, forming the internal bore of the seamless tube.

8

Pickling

The tube surface is chemically cleaned to remove scale, oxides, and other contaminants generated during hot processing.

9

Flat head

The tube end is flattened or prepared to achieve the required end condition and facilitate subsequent processing and inspection.

10

Cold Drawing and Cold Rolling

The tube is cold drawn and/or cold rolled to achieve the specified outside diameter, wall thickness, dimensional accuracy, and surface finish.

11

Inspection and Grinding

The tube is visually and dimensionally inspected, while localized surface imperfections are removed by controlled grinding when necessary.

12

Pipe Cutting

The finished tube is cut to the specified length with controlled dimensional accuracy and clean, square ends.

13

Straightening

The tube is straightened to meet the specified straightness requirements and ensure proper dimensional stability.

14

Degreasing

Residual oil, lubricant, and processing contaminants are removed from the tube surface to prepare it for heat treatment and further finishing.

15

Heat Treatment

The tubes undergo controlled heat treatment to obtain the required mechanical properties, metallurgical structure, and dimensional stability.

16

Physical and chemical testing

Samples and finished products are tested to verify chemical composition, mechanical properties, and other specified physical requirements.

17

NDT

Non-destructive testing is performed to detect internal or surface discontinuities without damaging the finished tube, using methods such as ultrasonic, eddy current, or other applicable techniques.

18

Hydrostatic testing

The tube is subjected to controlled hydraulic pressure to verify pressure resistance and identify potential leaks or integrity defects.

19

Surface inspection

The finished tube surface is inspected for visible defects, cleanliness, finish quality, and compliance with applicable specifications.

20

Marking

Product identification is permanently or clearly marked with relevant information such as size, grade, standard, heat number, and traceability details.

21

Packaging and warehousing

Qualified tubes are securely packaged and stored in the warehouse to protect them from damage, contamination, and corrosion before shipment.

22

Deliver goods

The finished products are prepared for dispatch and delivered according to the customer's order, packaging, documentation, and transportation requirements.