Innovative designs of an in-tank hydrogen valve towards direct metal laser sintering compatibility and fatigue life enhancement

Replacements of using fossil fuel by different types of renewable energy are the current development trend in the automotive industry towards sustainable vehicles. A hydrogen-powered car is a promising solution, in which the safe and smooth operation of the car is strongly depended on how an in-tank valve of a fuel-storage-system performs. The present paper introduces the investigations and innovations of structures of the mentioned valve, whose designs can be subjected to fabricate by direct metal laser sintering. Two parts of the valve were taken into considerations, including the largest female-thread and the body. While the threads were investigated in the proposed conditions via fatigue-life assessment, the bodies were only assessed after being built from the concepts, developed by structural optimisations and lattice implementation. The achieved results showed that within the same pre-treated conditions, the optimised valves have considerably higher fatigue life, but lower masses, than those of the original. It was also observed that the applications of pre-treatment by autofrettage could contribute significantly to life prolongation of the valves as compared to the non-treated ones. In addition, those essential features, such as powder-release channels, which make the developed valves compatible with DMLS, were implemented into the valve-designs to be able to ensure their successful prints. Finally, the results suggested that the second innovated structure of the lattice-valve is the best candidate, which could be additively produced for the upcoming experimental-validation phase of the demonstrated works.