The ESA Packings Division is partnering with the University DHBW Mannheim in Germany to evaluate packing materials for hydrogen applications. The university features an Amtec Packings Test stand, which was set up and put into operation last year as part of a student project. Initial experiments utilised expanded graphite packing rings under room temperature (RT) and static conditions. This year, a test was conducted using braided expanded graphite packing for fugitive emission service, following the ISO 15848 CO1 test cycle at both RT and 300 °C. The test was carried out at a pressure of 40 bar with an initial gland pressure of 50 MPa. The outcomes of this test were compared to those from a similar experiment using helium. The accompanying graph illustrates the leakage results.
The hydrogen leakage was marginally elevated but exhibited a comparable trend to the helium measurements. The testing program will proceed with additional packing materials to assess and compare the sealing effectiveness with both test gases. Furthermore, some of these findings will be showcased during a hydrogen workshop at the Valve World Conference in Düsseldorf this December.