Operating procedures should ensure that:

  • the system is properly leak tight and fully operational before use

    example: a quantitative leak check procedure is used

  • unwanted mixing of hydrogen with an oxidizer is prevented

    example: procedures should be in place for purging or otherwise removing air from a system before introducing hydrogen

  • the system is operated within design limits for temperature, pressure, and stress

    example: detailed cooldown procedures for a cryogenic system should be outlined in operating procedures to prevent excessive thermal stresses

  • handling (loading and unloading) precautions are followed for reactive or dangerous substances used in a hydrogen system

    example: use of pyrophoric compounds such as metal hydrides