Production

Incoming quality control of incoming metal is carried out by the technical control service of the plant and includes the following steps:

• analysis of the quality certificate and its verification for compliance with the workpiece;
• verification of geometric parameters;
• visual control;
• physical and mechanical tests;
• chemical analysis.

Sheets that have passed the incoming quality control are delivered to the production.

Each sheet is assigned a serial number, by which it is identified at all subsequent stages of redistribution.

Using a programmable thermal cutting machine, the edges of the sheet are trimmed around the entire perimeter to obtain the required workpiece dimensions.

With the help of milling and edge-cutting machines, a chamfer is applied with an angle corresponding to the thickness of the metal and the type of welded joint.
The heat-affected zone is also cleared of scale.

Using the method of rolling or step forming on sheet-bending equipment, the pipe billets are formed until they acquire a cylindrical shape with the required parameters along the entire length.

The formed tubular billet goes through the assembly stage, that is, bringing the longitudinal edges together while ensuring the required geometric parameters of the future pipe and welding technological strips.

Pre-performed at the root of a double-sided seam to prevent burn-through during subsequent welding.

Mechanized internal weld welding is performed.

Mechanized external weld welding is performed.

Checking the geometric parameters of the welded joint, visual inspection of the internal and external surfaces of the base metal and the welded joint of pipes.

Testing of pipes by pressure tests in order to control the continuity of the base metal and welded joint.

Non-destructive inspection of the welded joint. Ultrasonic control, X-ray control with recording of results.

Trimming of pipes is performed to obtain the required geometric parameters of the ends of the pipes in accordance with the reference documentation. The operation is performed on a pipe-beveling machine and allows you to ensure a strict perpendicular cutting relative to the pipe axis and end chamfering at the required angle.

The final acceptance of the pipe is carried out by the technical control service specialists of the plant as follows:

• Visual inspection of the internal and external surface of the pipe;
• Control of the geometric dimensions of the pipe:
  • Outer diameter;
  • Out-of-roundness of pipe ends;
  • Wall thickness;
  • General curvature;
  • Pipe length;
  • Chamfer angle and slope of cut.
• Ultrasonic control;
• Magnetic particle inspection of pipe ends;
• Mechanical laboratory tests of pipes in accordance with the requirements of the standard.

Each pipe is marked with the following information:

• trademark and company name;
• standard;
• pipe size;
• lot number;
• pipe number;
• steel grade;
• pipe length;
• date of manufacture of the pipe.

In the finished product warehouse, in accordance with the manufacturing plan, finished pipes are stored in special cells according to sizes and standards.