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…

The Panel considers two approaches to be acceptable. 

1. Stainless steel (corrosion resistant) lines embedded in concrete. This keeps the piping out of direct contact with the earth and provides a degree of physical protection from activities such as digging. 
2. Lines enclosed within a PVC sleeve. The PVC sleeve would usually be directly buried but could also be…

The HSP is not familiar with this particular fitting or its potential application in H2 service but can offer engineering judgment. Many similar compression-type swaged fittings are used in H2 service. These fittings must be used within the manufacturer recommendations for pressure, temperature, and fluid service. Deformation is also introduced into stainless steel tubing in other ways, such…

The primary safety standards for applicable to this piping in the U.S. are ASME B31.3, B31.12, and NFPA 2. The editions used should be those adopted by the local jurisdiction. Design of an LH2 piping system should always be conducted and reviewed by engineers experienced in cryogenic piping design. The equipment should also be installed per NFPA 2 and NFPA 55. IT is recommended that the piping…