Hydrogen Sealability: Alt. Designs, Materials, Facing

The hydrogen industry has been identified as a key decarbonization technology with its demand projected to grow five-fold, which can be seen by the influx of capital investment from the United States and globally. Several new projects are breaking ground with the goal of producing 50 million metric tons/year by 2050 in the United States and 500 million metric tons/year globally.

Currently, for several of the standards that are being used, such as ASME B31.12-2019 [1] (Hydrogen Piping and Pipelines), a majority of the sealing components call for standard gaskets from ASME B16.20 [2] and ASME B16.21 [3]. However, much is still relatively unknown regarding the potential leak rates of these standard gaskets or if the use poses any potential risks. In order to support the industry, we have performed EN 13555 [4] leak testing using 100% hydrogen across several different gaskets: ASME B16.20 [2] spiral wound, grooved metal gaskets, and alternate geometries and constructions, ASME B16.21 [3] rings with different materials including expanded polytetrafluoroethylene (ePTFE), nitrile butadiene rubber (NBR), and fluoroelastomer (FKM).

From what was observed, the permeability of hydrogen from the gaskets evaluated varies based on several different factors such as: sealing design, material, and facing material, some of which has a greater effect on creating a seal. This paper will discuss in depth the results of these gaskets tested with hydrogen and additionally make correlations to its sealability using helium.