Tenaris’s line pipe technology team has carried out an experimental activity to qualify medium and large diameter pipes of up to X70 grade for high-pressure gaseous hydrogen transportation with a hydrogen content of up to 100% at 200 bars.

Pressurized pipelines are considered a relevant solution for transporting molecular energy from the point of production or storage to the point of consumption.

"Due to the susceptibility of steel to hydrogen embrittlement the pipeline material needs to be qualified to demonstrate its readiness for hydrogen transportation and the new standards and guidelines require specific characterizations in gaseous hydrogen environments," said Tenaris Pipeline Technology Senior Director and Chairman of the DNV H2PIPE joint industry project on hydrogen pipelines, Philippe Darcis.

According to Tenaris, the hydrogen atoms can easily diffuse into the metal’s crystalline lattice due to their small size. The interaction with the metal’s microstructure can eventually result in the degradation of the metal’s mechanical properties, mainly involving a loss in mechanical ductility, reduced fracture toughness and loss of fatigue resistance. Purity, temperature, and pressure can affect the severity of the embrittlement. Thus, it is fundamental to determine how new and existing pipeline materials will react to the different compositions, pressures, and temperatures these pipelines will operate under.

Tenaris is addressing the need for reliable and high-performance materials in hydrogen environments with the development of THera, a new technology that offers a long-lasting and completely recyclable material with a verified product lifecycle, thanks to material testing in pressurized hydrogen environments.

“The experimental activity we carried out to qualify seamless and UOE LSAW pipes of up to grades X70, according to ASME B31.12 requirements, demonstrates the potential of THera solutions for hydrogen pipeline transportation of up to 200 bar with an extra safety margin,” said Darcis.