Fukui and ClassNK team up on hydrogen dual-fuel engine valves

September 10, 2025, by Aida Čučuk

Japan’s manufacturer Fukui Seisakusho and compatriot classification society ClassNK have signed a memorandum of understanding (MoU) to collaborate on ultra-high-pressure safety relief valves for hydrogen dual-fuel engines.

As reported, the parties agreed in 2023 to jointly conduct a study for the installation of safety relief valves for cargo tanks of liquefied hydrogen (LH2) carriers on actual ships. As a result of the study, a type approval certificate for the PILOT-type low-pressure safety relief valve (PSL-MD type) was issued in 2025.

On the back of that milestone, the parties have now agreed to cooperate on ultra-high-pressure safety relief valves for hydrogen dual-fuel engines that can reportedly meet advanced technical requirements (material resistance to hydrogen embrittlement, sealing performance, etc.) needed for hydrogen fuel supply systems.

It is understood that Fukui will manage the development of RPS-type (high-pressure compatible) safety relief valves for hydrogen dual-fuel engines, while ClassNK will be responsible for the review of the valves based on prescribed rules upon receiving an application for type approval.

Through the collaboration, both parties seek to contribute to the social implementation of propulsion systems using hydrogen as a fuel.