EUROPIPE's L485 (X70) pipes with epoxy-coated interior have been proven an excellent option for transportation of 100% hydrogen, the previous publication confirmed. According to the publication, the pipes are suitable for future ASME B31.12 standard build hydrogen pipelines.

Based on a preliminary test, steel was more than the properties assumed in a 100-bar pure hydrogen atmosphere standard. The epoxy's internal flow coating offers well-known benefits during the installation and the gas pipelines' operations. During EUROPIPE's research, many flow coatings were tested to evaluate their suitability in hydrogen transport.

In the recent test conducted by Salzgitter Mannesmann Research Company (SZMF), EUROPIPE's pipeline internally coated with epoxy-based flow proved suitable for transportation of pure hydrogen under 100 bar-pressure atmosphere.

The specimen under investigation were drawn from pipes internally lined with epoxy-based flow material TEKNOPOX 3296-06 (82 Vol.-% solid content) and TEKNOPOX 3297-00 (97 Vol.-% solid content). The coating materials were supplied by TEKNOS at (MÜLHEIM PIPECOATINGS (MPC)/. All the specimen's flow coating thicknesses were controlled between 61 µm and 120 µm.

Specimens' testing protocols were compliant with the API RP 5L2 for pipe's resistance to gas blistering and EN 10301/ISO 15741, used to test the pipe's resistance to variation in gas pressure (cyclic testing), as well as hydraulic-pressure blistering. Typically, these standards are widely used for non-corrosive gas qualification testing.

Usually, the "blistering tests" are carried out using nitrogen to simulate the possible effects of frequent pressure fluctuation on the internal flow coating. However, for the performed tests, pure hydrogen gas was used as a pressurizing gas to investigate whether hydrogen having a smaller molecular size would affect the resistance of the internal flow coating under spontaneous pressure fluctuation.

After all the tests were done, the specimen showed an impressive behaviour in a pure hydrogen environment, with no degradation, blistering, or reduction in adhesion. The test proved EUROPIPE’s pipes with internal flow coating by MÜLHEIM PIPECOATINGS are a perfect choice for future hydrogen pipelines.