Equipment inspection, testing and other maintenance can be thought of as either repairing existing equipment or replacing it in kind. Any changes made to the original design during maintenance activities should be handled through a formal Management of Change (MOC) process.
Proper and timely equipment maintenance is key to ensuring safe system operation. Reactive maintenance is unwise for equipment in hydrogen service. A systematic approach should be used to evaluate a facility's equipment and develop a cost-effective approach to maintaining its reliability. A maintenance plan and the results of performing maintenance should be documented and stewarded. A well-planned maintenance schedule should be implemented to prevent dangerous conditions before they occur. It may be acceptable to run non-critical equipment until it fails if there is redundancy in the facility design or if the component failure does not pose a safety issue. The following elements should be addressed:
- The maintenance strategy for each piece of equipment should be documented and communicated to the workers who will be performing the maintenance.
- The employer should develop and use a work permit system as a safe work practice to control workplace hazards during operations.
- Written procedures should detail the means for establishing that piping and equipment are purged and otherwise prepared to work on ("fit for maintenance").
- Maintenance of hydrogen storage vessels is very important since vessels generally pose the largest safety exposure to workers and facilities.
- Personnel must have the right tools and training as well as sufficient time and budget to perform their maintenance activities.
OSHA 1910 requires a mechanical integrity program for systems above 10,000 lb hydrogen, but this is a good concept to implement for all hydrogen systems.