CompositesWorld
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CompositesWorld.com 51 NEWS N E W S N S N E W S E N W S W Subsea Pipe Liner 500. Today, PETRONAS-related companies operate some 70% of the total 7,800 km of pipe- lines functioning in Malaysia. For a number of years, protective composite liners for pipeline rehabilitation have been a growth technology onshore (see "Learn More," p. 54), but no comparable ofshore tech- nology existed in 2009, when Walters met with PETRONAS executives to discuss solutions to SRB-related and other internal corrosion of that company's subsea pipelines. Together, they determined the solution was a corrosion- resistant liner, and in April 2011, APS Pipeline Rehabilitation division went to work on a liner design concept. Although APS designed and developed the liner system and is named as the joint inventor of the IFL technology, PETRONAS owns the IFL patent and trademark because it underwrote the development costs. APS is now negotiating with PETRONAS to secure an exclusive 20-year license to apply the intellectual property globally. Critical design factors Te liner was designed to be pulled through pipe lengths of up to 5 km with multiple 90° bends having radii as small as 5D (D = nominal pipe outside diameter; 5D is a radius bend length that is fve times the nominal pipe diameter). Each liner is custom designed and manufac- tured to match the original host pipeline bore, in nominal diameters from 152.5 mm to 457 mm (6 to 18 inches). To install the liner, then, it must be fexible enough to be folded and temporarily bound so it can be pulled through the pipe and around corners without damage or stoppage, and then subsequently infated. APS used Abaqus Unifed FEA software (Dassault Systèmes, Waltham, MA, US) to develop and simulate a liner composition and manufacturing process that would meet the necessary mechanical strength properties — primarily the theoretical towing loads, liner folding and infation forces, and the bending forces that would be incurred during installa- tion, when the liner would be pulled through an existing pipe, particularly around tight bends. APS envisioned the liner with a tightly woven, 100% aramid fber cylindrical core. Kevlar — a product of DuPont Protection Technologies (Richmond, VA, US) — was selected as the liner's structural aramid core largely due to its combi- nation of high tensile strength and high degree Light & flexible but abrasion/corrosion tough The Kevlar core of the InField Liner is a strong, fexible structure supporting an abrasion-resistant TPU exterior layer that contacts the damaged host pipe, and a corrosion-resistant polyvinylidene fuoride (PVDF) inner layer that is exposed to the corrosive service medium. Source | APS Outer Layer Abrasion-resistant BASF thermoplastic polyurethane Kevlar Fabric Seamless, woven aramid fbers from DuPont of fexibility, which would allow it to be manufactured, folded and spooled in long lengths. Termoplastic matrices were incorporated into the design as extruded layers, forming inner and outer barriers to chemical/corrosion resistance and giving the liner abrasion resistance during installation as it's pulled through the bends of the pipe pathway. Beyond the general design, each individual liner can be enhanced to meet envi- ronmental prerequisites, especially if it must withstand aggressive, hot, sour hydro- carbon service conditions of up to 110°C, or it can be planned and prepared for less Ready to install on arrival Here, an IFL, still wound on its transportation drum, is lifted aboard an ofshore platform in the Samarang oil feld, South China Sea. Inner Layer Media specifc: Hydrocarbon media at high temperatures, Solvay Solexis PVDF from Solvay Chemicals