1.    As of January 2024, we are not aware of any public data on incidents or investigations where a hydrogen fired steam boiler exploded.

2.    The potential for detonations within a boiler tube would depend on both the equivalence ratio of the hydrogen present and the diameter of the boiler tube.
a.    At a minimum, if the circumference of the tube is…

Yes, these would be ignitable mixtures.  In this case, it does not appear complicated geometry is involved, so 1200 psig pipe should be more than adequate to protect against internal deflagration. The most likely scenario is a "backfire," similar to a car, where ignition occurs too soon and shoots out the open end of the pipe. Consider using an inline deflagration flash arrestor on the…

Such a compressor should NOT be used for hydrogen. There are many issues with converting a compressor to hydrogen service. First and most important, this must be approved by the manufacturer. Examples of concerns for a non-hydrogen compressor used for hydrogen service include (but are not limited to): 

1. Are the materials compatible with hydrogen permeation, embrittlement,…

Even if a small experiment is being run inside a fume hood, the best practice is to use a dedicated vent line for hydrogen which vents hydrogen to a safe location outside.  This is especially recommended for planned venting.   This practice avoids situations where flammable mixtures could develop. Each system is unique and should be evaluated and approved for  use independently…

Cylinders used within a laboratory can be used safely by meeting the requirements prescribed in NFPA 2,
Hydrogen Technologies Code, and NFPA 45, Standard on Fire Protection for Laboratories Using Chemicals.
Special consideration should be given to both safe handling and storage of cylinders. Regarding lecture
size cylinders, their small size can make them susceptible to damage and…

Several organizations published a paper together on this topic in 2017 (see attached). Based on comparisons with tests and CFD simulations, the following conclusions were drawn:

1. The gas concentration for vapor cloud explosion blast load calculations for H2 jets can be limited to approximately 10% to 75%. Note that testing for H2-air VCEs in congested environments has been performed…

There are two parts for such a system to be effective. First, the system would have to activate quickly enough to establish a water mist throughout the region of interest (i.e., region occupied by a flammable gas mixture) before it could be ignited. This is challenging in terms of timing, and the impact of spraying water inside an enclosure filled with equipment not designed to get wet can be…

Explosion testing with hydrogen should be utilized only where there is not an established alternative and then only by personnel experienced in such testing. 
Testing with hydrogen is always a challenge and needs to be approached carefully due to significant differences in properties between hydrogen and propane. Hydrogen can develop significantly higher overpressures and preliminary…

The Panel has not received such inquiries. Section 14.2 of NFPA 69 Standard for Explosion Prevention Systems covers foam and mesh requirements. NFPA 69 states in 14.3.4 that the tests shall be conducted with a flammable gas/air mixture with a fundamental burning velocity representative of the burning velocities of flammable vapors expected in the intended applications.