Epoxy Gas Piperepair Kits Are Game-Changing Products In Emergency
New York is known for towering sky-scrapers and a dense metropolitan population. It is literally “The City That Never Sleeps.” But as autumn chilled the air, the natural gas supply, which was keeping a large swath of the dynamic city warm, was almost cut-off – unexpectedly and for an unknown length of time.
Workers were faced with a challenge — a 16-inch (40.6 cm) OD, carbon steel, natural gas pipeline, that operated at 99 psi (6.8 bar) had a 13.5-foot (4.1 m)-long gouge running along its length. At its worst point, the gouge was 1.5-inches (3.8 cm) wide, and 0.15-inches (3.8 mm) deep.
After thorough inspection, it was determined that the gouge was of sufficient size and depth to warrant an emergency repair as a necessary safety precaution. An unexpected rupture in the pipeline – an event that is always to be avoided — would be especially catastrophic in this case, given the fact that the damaged section of pipeline was buried in a densely populated area. Federal and state pipeline safety codes and regulations were very clear — an emergency repair was a necessary safety precaution. The pipeline’s owners, the natural gas company, was required by regulators to either install a repair, or entirely replace the section of damaged pipe with new.
Replace or Repair?
Replacing the damaged section would require shutting down the pipe – and disrupting service – for as long as it took to cut and remove the old pipe and reinstall a new section in its place. But, no matter how successful the installation, the scenario would leave the owners with angry and inconvenienced customers.
The other option, repair, seemed bleak – temporary fix after temporary fix until the pipe ultimately had to be replaced. That is until the owners learned about a high-tech solution that allowed for a fix, without shutting down the pipe, and at a fraction of the cost of installing new pipe. The owners turned to carbon fiber technology, specifically Neptune Research Inc. (NRI)’s Viper-Skin™ carbon fiber composite reinforcement system.
Viper-Skin™ is the first bi-axial, hybrid carbon and glass fiber polyurethane pre-impregnated system that blends the unsurpassed strength and stiffness of carbon with the ease of use of a moisture-cured, pre-impregnated laminate. This operator-qualified, engineered system was designed to conform to and is recognized by ASME PCC-2, ASME B31, ISO TS24817, DOT, API, and CSA Z662 standards for nonmetallic reinforcing solutions, thus ensuring product application integrity. As a result of the micro-controlled, wet-out process, nearly perfect resin content, and maximum, repeatable, strength properties are attainable. The time and cost associated with in-field saturation of the composite is removed from the equation altogether and eliminates the in conformity caused by human variability. The Viper-Skin™ solution conforms to all shapes, welds, and irregular geometries, and one size can be used on a variety of pipe diameters.
The pipeline’s owners decided. Repair rather than replace.
Into The Trench
With autumn’s chill quickly turning into winter’s bite, and the gouge a constant threat, there was no time to lose. The owners excavated the pipe and cleaned the steel surface according to NACE No. 2 / SSPC-SP10, the surface preparation standard for Near-White Blast Cleaning. This process removed any foreign matter, including paint and rust, in order to promote proper adhesion. It was time for the coatings crew and the NRI team to get to work.
Next, the gouge was ground down, and the crew used Syntho-Poxy™HC, a high-compression-strength, load-transferring, filler epoxy. Syntho-Poxy™ HC is a two-part epoxy compound that cures quickly at ambient temperature. Its high compressive strength and superior bond strength make it very suitable for repairing pitted metal and steel surfaces that are subjected to high pressure. When fully cured, the material produces a durable, resilient bond that is resistant to many solvents, hydrocarbons, and adverse environments.
Following the Syntho-Poxy™ HC application, the pipe was divided into sections and the crew was broken into teams in order to better stage and apply – a proper application of the epoxy is a quick process.
Syntho-Subsea™ LV is a unique blend of liquid epoxy, polymer, and aliphatic polyamine curing agents that is able to displace water from wet surfaces in order to make a permanent bond. The formulation is solvent-free to ensure safety and maximum technical performance. Kevlar® fibers are incorporated for reinforcement and viscosity management to achieve high-application rates – even in subsea applications. Providing permanent protection under the most adverse conditions, this formula is uniquely field-friendly and uses advanced, low-toxicity ingredients in a high-build brushable / rollable product. This versatile epoxy system can achieve high-performance characteristics, excellent adhesion, resistance to high pressures, resistance to high and low temperature extremes, as well as outstanding resistance to petroleum products and chemicals. Specified for use on both above-grade and below-grade applications, Syntho-Subsea™ LV epoxy can also be shipped non-regulated by USDOT, IATA, and IMO. It was a good choice for use in a densely populated area.
The team applied 30 mils of Syntho-Subsea™ LV over the first section of bare steel pipe. This effectively locked out any atmospheric conditions, providing corrosion protection. Then, while it was still wet, the team applied the Viper-Skin™ carbon fiber composite system at its calculated number of layers, over the first section of pipe.
Working methodically, and from epoxy repair kits, the team completed each individual section, first applying the Syntho-Subsea™ LV and following with the Viper-Skin™. When the last section was protected, and the entire length of the repair was complete, the pipeline was fully restored to its original integrity.
The Viper-Skin™ composite repair system eliminated the need to immediately replace the defective section of pipe. In the scope of one afternoon, working from piperepair kits, the Viper-Skin™ system was installed, returning the gas pipe to its original operating pressure, and enabling full pipeline operations – all with no disruptions to service.
Contact NRI and learn how we can keep your gas pipe running with our innovative epoxy products.