DNV Fully Certifies Thermoplastic Composite Tape for Pipes

PA12 is a fully non-metallic, corrosion-resistant solution. Due to the use of carbon fibers, it is particularly resistant to fatigue-based failures. Image courtesy of Strohm.

Thermoplastic composite pipe manufacturer Strohm (IJmuiden, The Netherlands) and specialty chemicals company Evonik (Essen, Germany) were recently awarded full certification from classification society DNV GL (Oslo, Norway) for their unidirectional carbon fiber tape known as VESTAPE PA12-CF.

The certification attests that the PA12 tape, which is used in Strohm’s thermoplastic composite pipe (TCP) solutions, is fit to use for dynamic sweet and sour hydrocarbons, as well as in water and gas injection applications, according to the DNV-ST-F119 standard.

“The invention of high-performance thermoplastic composite tapes such as PA12 offers innovative alternative solutions for pipeline infrastructure, which can potentially have lower costs and environmental footprint,” explains Ramin Moslemian, principal consultant at DNV and lead for non-metallic technologies.

“This is the case, not only for traditional oil and gas industries, but also for pipeline infrastructure of the energy transition for the transportation and storage of carbon dioxide [CO2] in carbon capture and storage, as well as hydrogen,” he adds.

TCP is a strong, non-corrosive, spoolable, lightweight technology that is delivered in long lengths. According to the developers, this can result in a significant reduction of transportation and installation costs. TCP is installed using small vessels or subsea pallets, which also reduces CO2 emissions. It is 100% recyclable.

Following a major investment and testing program, the two companies—in partnership with the Netherlands Aerospace Centre (NLR) (Amsterdam, The Netherlands)—have led intense efforts over the past five years on the development, qualification, and supply of PA12 for numerous TCP applications.

“Our fully non-metallic solution for load-bearing structures shows great potential to meet any challenges that corrosive environments can bring,” says Alexandre Paternoster, material technology team lead at Strohm. “Being applicable to both static and dynamic mode in hydrocarbon offers a great variety of addressable applications, including flowlines and risers.”

According to the companies, their approach seeks a fundamental understanding of the material to demonstrate the expected lifetime performance for products operating in challenging chemical, thermal, and mechanical environments. As part of their research, they have established a relationship between a pipe’s functional requirements and the performance characteristics of its materials.

NLR provided the main composite testing facilities to allow parallel dynamic and long-term testing, which it says sped up the process significantly when compared to traditional sequential testing.

“Testing carbon reinforced, saturated, PA12 specimens in situ in NORSOK fluid at elevated temperatures was quite a challenge,” says Rens Ubels, principal project engineer at NLR. “We successfully designed and built dedicated fatigue and stress rupture set-ups to be able to meet the test specifications and the safety and health regulations.”

According to the developers, PA12 is a fully non-metallic, corrosion-resistant solution. Due to the use of carbon fibers, it is particularly resistant to fatigue-based failures. According to the companies, this makes it an appropriate choice for any dynamic application from jumpers to flowlines and risers. This can include environments with sweet and sour hydrocarbons, as well as water and gas service.

The high stiffness of carbon fibers paired with the load transfer capability of PA12 also enables it for deepwater service and operating pressures up to 700 bar, as well as temperatures up to 80 °C, according to the companies. The material has been qualified for a lifetime of up to 30 years.

Going forward, further expansion of the research scope will include hydrogen and carbon capture, utilization, and storage, according to the companies.

“Developing a material class for disruptive technologies is always challenging. PA12 for Strohm’s TCP applications was no exception,” says Carsten Schuett, industrial and energy technology leader at Evonik. “The full application of the DNV’s standard’s approach to qualify the material has only added to the complexity. But, with the help of our partners, we finally succeeded in characterizing the material in unprecedented detail and unlocked its full potential. The resulting dataset can be used generically, removing the need for material qualification in further projects—which further enables us to use it for energy transition applications such as hydrogen transport and carbon capture utilization and storage.”

Looking ahead, Strohm says its track record and extensive offshore experience with TCP is a prerequisite to aiding the offshore energy industry’s transition from hydrocarbons to green alternatives. The company stresses its commitment to supporting the global industry’s goal of net zero carbon emissions.

“Hydrogen embrittlement and carbon dioxide dense phase transportation are of no concern for this material class,” says Caroline Justet, business growth executive at Strohm. “TCP is the preferred technology to unlock the potential of offshore wind-to-hydrogen, providing a safe and cost-effective solution to the challenges faced in today’s offshore hydrogen industry.”

Further information on the technology is available in a white paper titled, “The Material Qualification of PA12 Carbon Fibre for TCP application” at Strohm’s web site, which can be accessed at strohm.eu/tcp-application-whitepaper.

Source: Strohm, www.strohm.eu.