Fukui Seisakusho Co., Ltd. and ClassNK have signed an Memorandum of Understanding (MoU) for joint consideration of ultra-high pressure safety relief valves designed for the use in H₂ dual-fuel engines and hosted a signing ceremony at the Gastech 2025 exhibition being held in Milan, Italy.

Both parties agreed in 2023 to jointly conduct study for installation of safety relief valves for cargo tanks of liquefied H₂ carriers on actual ships and signed a MoU in Gastech 2023. As a result of this study, a type approval certificate for the PILOT-type low pressure safety relief valve (PSL-MD type) was issued this year.

Based on this achievement, they have now agreed to carry out joint consideration of ultra-high pressure safety relief valves for H₂ dual-fuel engines that can meet advanced technical requirements (material resistance to H₂ embrittlement, sealing performance, etc.) needed for H₂ fuel supply systems. The roles of each party are as follows:

• Fukui: Development of RPS-type (high pressure compatible) safety relief valves for H₂ dual-fuel engines
• ClassNK: Review of the valves based on prescribed rules upon receiving an application for type approval.

Through this collaboration under the MoU, both parties will contribute to the social implementation of propulsion systems using H₂ as a fuel.