Facilities should review their process systems to determine if they have valves installed that may be subject to this hazard. If so, facilities should conduct a detailed hazard analysis to determine the risk of valve failure. Detailed internal…

The practice of making gas mixtures in the laboratory should be eliminated, and gas mixtures with a known low hydrogen concentration should be purchased for use. The concentration of hydrogen used should be such that it is not possible to form an…

After this accident, a safety inspection team was organized. An investigation of this incident and an inspection of all other experimental equipment was conducted by the team. As a result of this inspection, the heaters are now hard-wired to the…

The primary lesson learned was that the active hydrogen facility and existing operating procedure, at the time of the accident, were sound. While this now has been determined, the previous form(s) of this system, associated documentation, and…

In the future, the laboratory will issue a memorandum about this incident to illustrate the need to wear safety glasses with side shields, store chemicals compatibly, take care when placing chemicals in the refrigerators for storage, and keep the…

1. Test safety system components even if they are new.
2. Do not rely on listening for valve movement as confirmation that a valve is closing; measure downstream pressure to determine if the valve is really sealing properly.
3. …

Procedures for safe handling of compressed gas cylinders, marking design of gas cylinders and connecting lines, and arrangement of cylinders were reviewed and modified as necessary. The spectrometer was returned to the manufacturer for a careful…

In addition to the probable causes listed above, the lack of a standard operating procedure for hydrogen leak detection was one of the probable causes of this incident. Additional contributing factors included the following:
- Severe pipe…

The company investigation revealed that the incident arose because insufficient water was added to the batch. This resulted in a rapid increase in temperature and evolution of hydrogen gas following the addition of aluminum powder in the last…

The incident was the result of a combination of factors leading to exceptional temperature conditions that were not taken into account in the mechanical design of the reactor. Corrective actions that were implemented by the plant management…

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…

1. The presence of other flammable impurities (e.g., oil carryover from compressors, hydrocarbon contamination of the gas) is an additional hazard and should be eliminated before cryogenic purification.
2. Potential sources of oxygen in…

Three root-causes were noted during the investigation: (1) the use of incompatible materials in the manufacturing of the PRD valve, (2) improper assembly resulting in over-torquing of the inner assembly, and (3) over-hardening of the inner…

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. Carbon steel Nelson curve methodology cannot be depended on to prevent HTHA equipment failures and cannot be reliably used to predict the occurrence of HTHA equipment damage. Revisions to recommended practices should be considered…