Vitaly Gorlachev
Deputy director, production
Coating repair
Coating repair on trunk pipelines
We open the live pipeline in short sections, strip the old coating, apply cold-applied tape and check every stage. More than 40 km of coating repaired.
KM 01
What the work includes
- Preparatory work: route axis, burial depth, crossings with other utilities, temporary access roads.
- Earthworks: topsoil removal, mechanical and manual excavation, soil tamping, backfilling, land restoration.
- Dewatering where the groundwater level is high.
- Removal and reinstallation of weights.
- Cleaning: removal of damaged coating, rust, dust, moisture and oil stains.
- Non-destructive testing of the pipe condition.
- Coating work: priming and tape application.
- Reconnection of the test leads of cathodic protection equipment.
- Coating quality control: continuity, thickness, adhesion.
KM 02
How the repair goes
- 01
Preparation and safety
We complete permits and briefings, carry out electrometric sounding and mark the repair locations. Work follows the technical regulations in force.
- 02
Opening the pipeline
The pipe position is confirmed by trial pits, manual probing and instruments. The excavator bucket stays at least 0.5 m from the pipe; in practice the open section is no longer than 15 m.
- 03
Sheet piling and dewatering
Where groundwater is high we drive sheet piles and install dewatering: the slopes are secured and the risk of collapse is kept to a minimum.
- 04
Surface cleaning
With scrapers and brushes to grade 4 of VSN 008-88. Scrapers do not damage the pipe body. Laboratory specialists check the metal for defects.
- 05
Primer and tape
Primer goes on in an even layer by roller and brush. Tape is applied with a hand-driven wrapping device that keeps overlap and tension constant around the pipe.
- 06
Inspection and backfill
We check coating thickness, adhesion and continuity. Backfilling includes manual tamping of soil under the bottom of the pipe.
KM 03
Why cold-applied tape
The loaded wrapping device weighs under 100 kg for a 1200 mm pipe. The load on the gas pipeline is minimal, so work is possible even where the pipe body has defects.
BPI tape needs no heating next to the works, which rules out ignition.
KM 04
Photos from site
Company photographs
KM 05
Questions and answers
How much coating does a crew repair per day?
In good conditions, 40–45 m on a pipeline 1000–1200 mm in diameter.
What happens where groundwater is high?
Sheet piles and dewatering units are used. This secures the trench slopes.
How is the new coating checked?
The company's laboratory specialists check thickness, adhesion and continuity, with visual inspection throughout the work.
Describe your asset and we will scope the work
Diameter, length, product, commissioning year and earlier survey documents help us answer to the point.