Renovation of steel pipes

Ø 219-1420 mm

Renovation of steel pipes

In 2010, our company set up a site to restore steel pipes that were in service.

This made it possible to transfer a certain amount of repair work from the highway to the stationary factory conditions.

This way makes it possible to increase the productivity and quality of repair and restoration work on main pipelines while reducing costs by preserving the main component of the pipeline, namely pipes.

Stages of work

Workson the restoration of steel pipes

Pipe restoration workis carried out in several stages:

Visual control

Assessment of pipe appearance, mechanical damage, metallurgical defects and corrosion. Rejection is carried out in accordance with VNS 012-88 part 1 clause 4.6.

Instrumental control

It is carried outto determine the ovality at the ends, the curvature of the pipe, the size of the defects detected during visual inspection. Rejection is carried out in accordance with VNS 012-88 part 1 clause 4.5.

Pipe cleaning

The pipes are cleanedof insulation coating residues and dirt using a high-pressure water jet (which does not disturb the surface structure of the pipe metal).

Measuring and selective control

Conducting 100% visual and spot checks with an ultrasonic thickness gauge. Based on the results of the instrumental and instrumental inspection, defect reports for the diagnosed pipe are drawn up.

Replacement of defective pipe sections

Pipe sectionswith defects that do not meet the requirements of regulatory documents must be removed. Defective pipe sections shall be replaced with coils.

Welding pipe joints

Welding of pipe joints and welding of coils is performed in accordance with VNS 006-89 according to separate instructions. Welding equipment and welding methods are protected by patents of Ukraine.

Ultrasound and X-ray inspection

All welded ring joints during pipe welding and coil welding are subject to 100% X-ray and ultrasonic inspection in accordance with VSN 012-88. The quality control of welding operations is carried out by operational control, external inspection, checking the integrity of the welded metal using physical non-destructive testing methods (ultrasonic testing, radiographic testing).

Repair of the pipe body

The pipe body is repairedby manual arc welding in accordance with RD 51-108-86 (Instruction on the technology of welding and cutting pipes during repair and restoration works on main gas pipelines). The repaired sections are grinded using angle grinders.

Mechanical processing of pipe edges

After all the restoration work is completed, the pipe edges are machined using machine tools.

Preparing for the application of an anti-corrosion coating

The repaired pipes are subjected to shot blasting, dust removal and degreasing, which allows us to clean the surface of the pipes and prepare them for anti-corrosion coating.

Hydraulic testing

At the customer’s request, the pipes are additionally hydrotested in accordance with the ND.

Formalisation of the conclusion

Issuance of a conclusion on the numbered pipe indicating all geometric and mechanical parameters of the pipe, repair sites, references to non-destructive testing protocols and permissible operating pressure.

Corrosion-resistant insulation

Anti-corrosion coating of reconditioned steel pipes

The rehabilitated pipes can be coated with an external anticorrosive coating of extruded polyethylene in accordance with TU U-27.2-31017014-001: 2005 or an external polyurethane coating using an airless application system. It is also possible to apply an internal anticorrosive coating with epoxy compositions in accordance with TU U-27.2-31017014-003: 2011.

  • External anti-corrosion coating with extruded polyethylene
  • External polyurethane coating
  • Internal anti-corrosion coating

Anti-corrosion insulation of reconditioned steel pipes

External anti-corrosion coating based on extruded polyethylene/polypropylene
  • 3-layer external anti-corrosion coating based on extruded polyethylene (3PE)
  • 2-layer external anti-corrosion coating based on extruded polyethylene (2PE)
  • 3-layer external anti-corrosion coating based on extruded polypropylene (3PP)
External protective anti-corrosion epoxy and polyurethane coatings
  • Polyurethane external anti-corrosion coating
  • Epoxy external anti-corrosion coating
Internal anti-corrosion coatings
  • Internal smooth epoxy coating (40-150 microns)
  • Internal anti-corrosion coating (200-1000 microns)