Gasket technology
Hard-metal gaskets between the body and bonnet are necessary in hydrogen processes. Softer metals are too porous for the application. The harder, nonporous materials have significantly higher operating temperatures exceeding 250°C. However, metal gaskets require more accurate machining. If the body or the gasket is not perfectly round and precisely within tolerances, it will not seal effectively. For this reason, valve bodies must be precisely machined.