Weld-Free Offshore Pipe Repair Using Lokring® Technology
How PipeServ delivered a safe, weld-free replacement of an offshore closed drain line using Lokring® cold-weld technology—reducing shutdown time, eliminating hot work, and minimising hydrotesting requirements.
During a planned offshore shutdown, a leaking closed drain line required replacement to maintain the integrity of the process system. The existing elbow had been temporarily repaired to keep the asset operational until the shutdown. The challenge was to safely install the replacement spool while avoiding hot work, minimising shutdown duration, and reducing the scope of hydrotesting.
Our Solution
PipeServ supplied and installed a Lokring® cold-weld flange on the replacement spool, providing a permanent, weld-free connection without the need for hot work. To further reduce shutdown time, an EST Flange Tester was used to hydrotest only the new Lokring connection rather than the entire closed drain system. This approach delivered a safe, efficient installation while significantly reducing project time, testing requirements, and operational disruption.
Results
PipeServ successfully completed the offshore closed drain line replacement without the need for welding or hot work. The Lokring® installation and targeted hydrotest reduced shutdown duration, improved personnel safety, and minimised testing requirements by isolating only the new connection. The project demonstrated how combining Lokring® cold-weld technology with EST hydrotesting equipment provides a faster, safer, and more cost-effective solution for offshore piping modifications.
Frequently Asked Questions
Why choose Lokring® instead of welding for offshore pipe repairs?
Lokring® provides a permanent, cold-weld mechanical connection that eliminates the need for hot work permits, welding equipment, and post-weld inspections. This improves safety, reduces installation time, and minimises shutdown durations, making it an ideal solution for offshore maintenance and brownfield modifications.
What are the advantages of using an EST Flange Tester with Lokring® installations?
An EST Flange Tester allows only the newly installed Lokring® connection to be hydrotested rather than the entire piping system. This significantly reduces test water volumes, setup time, and shutdown duration while providing confidence that the new connection has been successfully pressure tested before returning the system to service.
Is a Lokring® connection suitable for permanent offshore service?
Yes. Lokring® fittings are engineered as permanent mechanical pipe connections and are widely used throughout the offshore oil and gas industry. When installed by trained technicians and selected for the correct application, they provide a reliable, leak-tight joint without the need for welding.
How much time and cost can Lokring® save compared to conventional welded repairs offshore?
Lokring® eliminates many of the activities associated with conventional welded repairs, including hot work permits, welding, NDT, fire watches, and extensive isolation requirements. This can reduce installation costs by up to 70% compared to traditional welding for many offshore piping modifications. These savings are achieved before considering the often much greater financial impact of reduced production downtime and shorter shutdown durations, making Lokring® a highly cost-effective solution for offshore maintenance and brownfield projects.
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