1. Consider periodic testing of breakaway device.
2. Consider determining shear force limit of vehicle receptacle adapter fittings.

Mechanical pressure gauges tend to be imprecise if only used in a narrow portion of the full scale. Digital transducers, although slightly more expensive, offer much more precision. The event happened because the set pressure was only 10% of full…

Corrective actions included replacing the breakaway with a new one, which restored normal operation of the dispenser.

Verify and periodically inspect the pull/separation force adjustment if the breakaway is so equipped.

Additional…

1. Management must ensure that operating decisions are not based primarily on cost and production. Performance goals and operating risks must be effectively communicated to all employees. Facility management must set safe, achievable operating…

1. It is important to understand the requirements and standards associated with safe equipment design (especially electrical equipment containing an internal ignition source with flammable gas) in potentially explosive atmosphere environments…

1. Upgrade the liquid hydrogen pump control system to shut down operation of the pump and protect the system when malfunctions like leaks, pump cavitation, or loss of purge gas occur.
2. Verify that maintenance procedures used for…

1. Increase physical protection, shielding, and securing of transported hydrogen tube valves, piping, and fittings from multi-directional forces that are likely to occur during accidents, including rollovers. Reference: 49 Code of Federal…

LESSONS LEARNED:

1. Compressed gas cylinder caps can be very difficult to open as rust often occurs in the threads.
2. There are wrenches specifically designed to remove…

1. The trailer involved in the incident used a frangible burst disk based upon the proprietary metal compound designated as Inconel #600. Random sampling of similar pressure relief devices from the same trailer showed that all of them failed at…

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…

Many accidents reported from paper mills have much in common with this incident. Microorganisms in the process water with pulp produce hydrogen gas that mixes with air to form an explosive atmosphere. The ignition source is typically sparks…

A tool is provided for removing the cylinder cap that cannot contact the valve.

Consider design review of all adapter fittings.

The following corrective actions have been taken:

• The non-return valve was dismantled, cleaned, and tested. Following positive testing, the system was restarted and pressurized without any further malfunctioning.
• The…

1. Evaluate any change in normal procedures or conditions for storage of aluminum hydride products. In this case, the aluminum hydride material was typically stored at -35°C in the glove box freezer. However, due to a change in glove boxes, this…

Metallurgical examination of the two failed disks by light optical microscopy (LOM), scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopic analysis (EDS) found them to be fabricated from pure nickel with evidence of…

Mounting hardware incorporated polymeric braces not suitable for long-term exposure to sunlight and temperature extremes. With time, the polymeric materials had disintegrated, allowing the mounting brackets to become loose. In addition, the…

The possible outcomes from new maintenance scenarios can be predicted by using an accurate simulation. The proposed filter change-out maintenance was studied to identify conditions to which the catalyst might be exposed and a mock-up of the…

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 investigation team concluded that hydrogen gas was released through a failed 19-inch diameter gasket and ignited under the roof of the compressor shed where it was partially confined. Some gas escaped from the shed prior to the explosion, but…