Personnel should be properly supervised, and supervisors should be aware of the activities of their personnel. Personnel must be motivated to adhere to established policies and procedures. All personnel associated with potentially hazardous work…

• All tank trailers should have a safely accessible auxiliary shut off valve in case of spills.
• Emergency personnel need to have access to all of the appropriate protective clothing, including shoes. Liquid hydrogen is stored at 20…

Standard procedure must be followed in all cases. Assumptions are made at great risk. Risk also increases with complacency.

Fail-safe position of control valves in supply lines must be set correctly to prevent damage to pressure vessels.

Recommendation

Set all valves for fail safe operation (open or closed) according to needs before installation…

All valves and connectors should be clearly labeled to minimize chances for mis-connection. All technicians must be trained on proper procedures for both taking systems offline and bringing them back online.

Valves for compressed hydrogen…

First, it appears that the system may not have been vented properly. CGA G-5.5 should be used for determining safe locations based on the variables of the specific setup. Also, if the compressor was tied to a storage system, a backflow prevention…

1. The plant tried to increase production and decrease workload, but failed to notice the potential negative outcomes of this change.
2. It is necessary to thoroughly simulate all potential negative outcomes of a change in procedures…

Investigation determined that internal galling has caused the failure rendering the needle valve unusable. The galling was caused by a stainless steel stem acting against a stainless steel seat. This failure mode had been observed before and the…

Included inspection on monthly preventive maintenance plan and evaluated alternate materials for better cold-weather performance.

To prevent a similar flashback, the following measures have been taken:

1. The valve is opened slowly to avoid a major leading shock into the venting line.
2. A special nozzle (Laval or similar) is mounted directly after the…

Recommendations:

1. The using organization should define necessary activities in order to place hydrogen systems in long-term periods of inactivity. The defined activities should address requirements for rendering inert, isolation (i.…

• Active GH2 sensors should be installed and continuously monitored in all enclosed buildings near GH2 sources. All buildings near areas where hydrogen is used should be designed to preclude GH2 entrapment (e.g., sloping roof with…

1. Follow the rules (e.g., using a torque-amplifying device requires supervisor approval).
2. Some valves are susceptible to disassembly, with potentially significant consequences, if excessive torque is applied to the handwheel.…

The following actions were proposed as a result of this incident:

•  The company in charge of valve calibration and maintenance will be subject to approval of the plant service inspection team.
•  Plant operating…

Personnel were focused on the AGES system test and results, not the compatibility of the test equipment. The manual valve was needed to successfully test the system, however the fact that this particular valve could not accommodate the full…

An important aspect of the reliability of a valve is the condition of the stem seal which tends to deteriorate with time and wear. Valves used in hydrogen service should be packed with the correct valve packing material and periodically checked…

1. Maintenance work scopes must be adhered to. If added work is approved, it must be tracked and reviewed to ensure that the equipment is inspected by operations personnel. Scheduled work and extra work should be listed and checked off for…

Excessive venting of hydrogen from the tank due to lower facility consumption, in combination with extreme temperature conditions, placed thermal stress on the gland nut, causing a leak. The low consumption of hydrogen resulted from the shutdown…

1. Ensure that equipment and materials exposed to hydrogen are compatible with a hydrogen environment (even hydrogen-service-rated equipment).

2. Equipment designs in a hydrogen environment that use the fracture toughness for 17-4…