Disclaimer: The Lessons Learned Database includes the incidents that were voluntarily submitted. The database is not a comprehensive source for all incidents that have occurred.
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…
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…
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…
Several procedural and design changes should be considered for the future:
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…
In the future, refining, petrochemical, and chemical industries need to review material verification programs to ensure that the maintenance procedures include sufficient controls and positive material identification (PMI) testing to prevent…
The lesson to pass on is that ventilation is critical in UPS battery rooms. Great care should be taken to ensure that the ventilation system is operational and brings in enough outdoor air to properly ventilate the enclosure.
Electrical…
An important lesson to be derived from this incident is the need to carefully engineer and test all repairs and modifications to high-pressure process equipment.
The above described events are an indication of a potential licensee/vendor interface problem. Based on the information received, the vendor was not completely informed via the purchase specifications regarding the service condition to which the…
The investigative report noted that the explosion could have been prevented by (among other things) a continuous gas analyzer test of oxygen and hydrogen product purity. The continuous analyzer should be interlocked to shut the electrolyzer down…
Work documentation (work orders and baseline drawings) should reflect the current system configuration.
Recommendations
In addition to resealing the glove box window, a positive pressure of argon gas was maintained inside the glove box while the course of action was planned. Subsequently, the glove box was cleaned up by specialized hazardous materials personnel…
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…
Because of the near invisibility of a hydrogen flame in daylight and hydrogen's extremely low ignition coefficient, if a known leak is present (e.g., an audible hissing), ignition should always be presumed. The primary cause of this incident…
It is characteristic of silver/zinc batteries to outgas both hydrogen and oxygen for several hours after discharge. Also, in the future, the battery should be properly secured inside the container.
Normally hydrogen fires are not extinguished until the supply of hydrogen has been shut off due to the danger of re-ignition and explosion. During a gas leak/fire, it is important to shut off the source of the hydrogen if it is safe to do so. If…
Lessons Learned The site initiated the establishment of a field patrol and strengthened their onsite monitoring of mechanical equipment during a plant-wide temperature rise.
Key:
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