Repair extends pipe life by 20 years

Decision to mend, rather than replace, reaps huge payback for EDF

Henkel LOCTITE pipe repair technology at EDF Energy.JPG

EDF puts its trust in Henkel LOCTITE.JPG

The decision by power generation company EDF to repair, rather than replace, leaking pipework at its nuclear power plant in Bugey has proved hugely beneficial both practically and financially. Maintenance engineers used Henkel’s LOCTITE Composite Pipe Repair System to restore the integrity of 170m of fresh water pipes, a process that was undertaken without the need to stop production and at a cost that was 35% less than the replacement value.

The LOCTITE Composite Pipe Repair System is a sustainable solution that has already proven its cost-effectiveness across many industrial sectors, including energy and petrochemical production, paper converting, water treatment and chemical processing. And, in common with other users, it has enabled EDF to extend the service life of its damaged steel pipes by up to 20 years with a repair that is certified to the global quality standard, ISO 24817.

40 years of service

Located around 75km from the Swiss border, the EDF plant occupies 100 hectares and houses four pressurised water reactors. A network of pipes supplying raw water to the demineralisation station date from the plant’s original construction and, after 40 years of service, some sections required multiple and complex repairs.

The renewal of the DN168 and DN508 sections would have required a complete by-pass system to be installed to ensure the continuity of the cooling process. So, engineers from EDF’s Valves and Boilers Department sought a repair solution that would not only avoid the high cost of pipe replacement, but also the expense and time involved in installing the temporary by-pass.

“EDF chose the LOCTITE Composite Pipe Repair System because it is an all-in-one solution designed to repair damaged or corroded elements where high impact resistance and protection against corrosion and external attack are required,” explains Henkel. “All system elements, from the effectiveness of the product and process to the way the system is applied and managed in the field, are covered by the certification process.”

Rotor blades

Central to the system is a resin-based composite material reinforced with fibres. It is similar to materials developed by Henkel under its LOCTITE brand that are successfully serving manufacturers of rotor blades for wind power generation or lightweight components for the automotive industry.

Applied at ambient temperature, it is suitable for repairing punctures and other wall defects and, depending on the type of fault, the process can generally be carried out under pressure to eliminate downtime.

As well as metal pipes, the system is also suitable for repairing conduits, tanks and components with complex geometries, such as bends, tees, reducers and flanges.

The process

Every repair is different but, typically, the first step in the process is to clean and sandblast the surface of the damaged area. As this treatment exposes the site to flash rust, the corrosion inhibitor LOCTITE SF 7515 is applied to provide immediate, temporary protection.

“As appropriate, the original outer pipe diameters are then restored by filling the cavities with LOCTITE EA 3478, a proven ferro-silicone filled epoxy compound that provides outstanding compression strength,” adds Henkel This product was specifically developed for renewing surfaces subject to compression, thrust, impact and harsh environments.

The pipe is then wrapped with high-strength, glass carbon-fibre tape, LOCTITE PC 5085, that has been impregnated with the temperature-resistant, two-part epoxy resin LOCTITE PC 7210; this product is designed for bonding steel substrates and exhibits exceptionally high adhesion.

The final step is to seal the repaired section with the sprayable ceramic topcoat, LOCTITE PC 7255, a two-part epoxy that is also WRAS approved. The resultant composite repair effectively reinforces steel pipes for continued duty under high pressure and thermal cycling, while increasing their resistance to internal and external attack.

As part of the solution package, Henkel provided EDF with calculations of the proposed repair designs. These differ from project to project, depending on a range of parameters, such as the forces acting on the pipeline, temperature, pressure and extent of damage. Specially developed software then determined how the repair should be executed. This, too, is covered by ISO 24817 certification, so EDF could be certain of the safety and efficiency of the process.

Huge potential

Steel pipes and pipelines are extremely capital intensive, irrespective of whether they are used to transport gas, water, crude oil, waste water or any other medium. So, the lifetime of these transport systems is a critical factor for any operator; it pays to extend their service life for as long as possible beyond their planned amortisation and depreciation period.

“The LOCTITE Composite Repair System brings together a series of products that have been field proven over many years,” states the company. “Their combined attributes create a method of pipe repair that is attracting a lot of attention across the processing, petrochemical and power generation sectors, because it can increase pipe lifetime by up to 20 years. This benefit, in combination with the fact that the repair can be undertaken without stopping production, represents huge operational cost savings.”

The decision by EDF to repair, not replace, leaking pipework has proved hugely beneficial.
The decision by EDF to repair, not replace, leaking pipework has proved hugely beneficial.

Henkel Ltd

Wood Lane End
Hemel Hempstead
HP2 4RQ
UNITED KINGDOM

+44 (0)1442 278000

technicalservice.loctite@uk.henkel.com

www.henkel.com

More from Henkel Ltd

Are adhesives part of your repair process?

Posted 6 days ago

Henkel and Nexa3D sign material development deal

Posted 3 weeks ago

3D Printing resins launched for healthcare applications

Posted 1 month ago

Henkel products prove winning formula

Posted 2 months ago

Henkel and BRABUS strengthen windscreen bond

Posted 2 months ago

Henkel-Nexa3D collaboration has healthy outcome

Posted 2 months ago

Flame-retardant Henkel adhesives play key role in fire suppression

Posted 2 months ago

Extending your Horizons

Posted 3 months ago

New range of multi-purpose, handheld dispensers

Posted 4 months ago

Biodegradable cleaner and de-greaser

Posted 4 months ago

Missing out on the benefits of structural bonding?

Posted 5 months ago

Henkel’s Technomelt in a mould of its own

Posted 6 months ago

Popular resource emphasises the importance of thread locking

Posted 6 months ago

Fast and durable plastics bonding

Posted 6 months ago

Five day machine repair reduced to 8 hours

Posted 7 months ago

Creating a vision: windscreen bonding webinar

Posted 7 months ago

Threadlocker resolves quality challenge

Posted 8 months ago

A view on liquid vs compression gaskets

Posted 9 months ago

Threadlocker makes light work of solar panels

Posted 10 months ago

New repeatable threadlocking dispenser

Posted 10 months ago

Henkel Loctite highlights advantages of threadlocker

Posted 10 months ago

XPLORE: the new e-learning platform from Loctite

Posted 11 months ago

Dangers of vibrational fastener loosening

Posted 1 year ago

More applications

Login / Sign up