A seven-day window was all the German company Rädlinger Primus Line GmbH
could work with when rehabilitating over 600 m of a 10 in (250 mm) diameter
carbon steel service pipeline in Guatemala. Primus Line recently performed a rehabilitation
project of a 10 in (250 mm) diameter carbon steel service pipeline with PN 10 (150 psi) in a river crossing area. The pipeline starts at a wharf and terminates in a tank terminal. Tankers discharge petrochemical products weekly.
The carbon steel pipeline suffering corrosion runs through a concrete gutter covered by steel plates along the docking edge of the wharf. Other parts of the pipeline run underground and are surrounded by concrete.The pipeline was operated with different media and therefore had to be pigged continuously, which also accelerated the corrosion process.
The oil industry is facing new challenges as a result of damage to steel pipelines caused by
internal corrosion. Possible leakage might cause significant environmental damage; they also mean increased costs, loss of production or even loss of reputation for network operators. Primus Line® is suitable for the renovation of oil pipelines due to the medium-specific inner layer, and acts as a corrosion barrier between the transported fluid and the host pipe. The conveyed fluid covers media from categories as diesel, crude oils, fuel oils, oil slag and other refined products.
This pipeline in Guatemala, in an environmentally-sensitive and difficult-to-access area, cannot be shut down for more than seven days because incoming vessels cannot be rescheduled. The total replacement of the pipeline was consequently not an option for the client. The Primus Line® System of DN 250 PN 10 was the best option to minimise cost, avoid downtime and significantly extend the lifespan of the existing pipeline whilst staying within the seven-day rehabilitation window offered at this location.
The 10 in (250 mm) diameter host pipe was de-pressurised, isolated from the pipe network and preparatory cleaning was performed by mechanical scraping. The cleaned pipe was thus made ready for the insertion of the Primus Line® DN 250 liner which was sent pre-folded to the construction site on a single transport spool. Thanks to its pre-folded condition, the pulling forces required to navigate the unspooled Primus Line®
through the pipeline were significantly reduced. Two sections of the DN 250 liner were installed by using a pulling winch with a maximum force of 1.2 t (12 kN).
After assembling four Primus Line® connectors, each rehabilitated section was hydro-tested. With the reintegration of the renewed sections into the existing pipeline network, the rehabilitation works of the product pipeline were completed successfully in the short window between two tanker discharge cycles.
The Primus Line liner being unspooled at the installation site.
Primus Line® is a flexible aramid-reinforced pressure hose seamlessly produced at the Primus Line® factory in Germany in lengths of up to nearly 15,000 ft (4,500 m). Numerous certifications permit the installation of the Primus Line® technology in high-pressure oil and gas industry pipelines. A unique advantage of the Primus Line® system compared to rigid rehabilitation systems is the fact that Primus Line® remains a flexible pipeline in all operating conditions after installation in the host pipe. Because the Primus Line®
system is highly flexible, it can be pulled through bends of up to 45°; installation lengths of up to nearly 15,000′ (or 4,500 m) are possible.
Primus Line® can also be installed in host pipes that are still flooded with water. During installation, Primus Line® is navigated through any residual fluids without difficulty andis a self-supporting system which does not require attachment to its host pipe. The system carries all the internal pressure and only needs the host pipe to carry the soil loads. Properly installed, there will remain an annulus gap between the Primus Liner and the inner wall of the host pipe. Single-layer Primus Line® DN 250 PN 20 can accommodate an operating pressure of up to 20 bar.