I am communicating with a company that is exploring this technology for an application involving a mixture of flammable gases, including hydrogen.

There is limited published research on the effect of water sprays on hydrogen deflagrations and deflagration-to-detonation transition, and more extensive data on water spray effects on hydrocarbon gas explosions. The results show the benefits, where there are benefits, to be highly scenario dependent. For example, Carlson et al. (Atomics International report, 1973) described hydrogen…

The lesson learned (LL) article referenced in the question cites an incident that occurred in December 1969. While there may have been other accidents, the HSP does not have any other LL articles on alkaline water electrolysis explosions. In the LL article that was updated in 2017, the technology described employs a potassium hydroxide (KOH) electrolyte solution. The KOH electrolyte is held by…

No, but it is always necessary to determine the possibility of an adverse chemical reaction with the particular material being used for the mesh.

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.

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…

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…

Example safety guidelines are listed below but may not be all-inclusive (e.g., they do not cover general practices such as lockout/tagout, management of change, job safety analysis), and most are the same as for gaseous hydrogen. Also reference NFPA 2 and CGA documents such as H-3, H-5, and H-7. Additional safety training material can also be found on the following link to courses and…

Flare-less compression style fittings are commonly used. Choose tubing materials and tube wall thicknesses suitable for hydrogen and pressures you are using. Make sure all tubing joints are properly made, mechanically supported to minimize stress and vibration, are in a ventilated space, and are easily accessible for inspection and leak testing. 

In general, indoor storage should be limited and the use of hydrogen indoors should be the least necessary. Look to store flammable gases outdoors in dedicated protected area when practicable. Check to see what adopted building and fire codes in your jurisdiction say. NFPA 2, Hydrogen Technology Code, Sections 6.4.1 and 16.3 prescribe requirements to limit hydrogen storage and use in…