A Study on Sealing Behavior of Rubber O-Ring in High Pressure Hydrogen Gas

Rubber O-rings installed in hydrogen tanks for fuel cell electric vehicles are repeatedly exposed to high pressure hydrogen gas. Exposure to high pressure gas sometimes causes cracks as a result of blistering after decompression. The degree of blister damage is influenced by material, environmental conditions such as decompression rate, and sealing shape such as squeeze ratio. Focusing on environmental conditions out of these influential factors, in this study, a high pressure hydrogen durability tester which exposes rubber O-rings repeatedly to high pressure hydrogen gas at arbitrary test conditions was developed. Using this tester, the influence of hydrogen pressure and temperature on blister damage and permeability was investigated for sealing materials used conventionally for high pressure equipment.