Hydrogen Pressure Vessel Cutout

This part is a cutout from a full-scale 300 bar composite Type IV pressure vessel for hydrogen storage (liner removed). This vessel was produced in a joint project together with industry partners (for more information, download our whitepaper). It consists of a metallic boss, dome reinforcement layers produced with Fiber Patch Placement, and a filament winding overwrap. Cevotec’s mission is to realize the FPP reinforcement patches in the dome region, optimized to improve the stress distribution and mechanical performance of the vessel domes, so that the total amount of fiber material needed can be reduced and the storage efficiency of the tank increases. Compared to higher pressure tanks (e.g. 700-bar-class), the chosen 300-bar-class demonstrator is specifically challenging due to the limited amount of layers in the original vessel design which can be optimized.

Process: How was this part produced?

The thermoplastic liner, together with the metallic boss assembly, was provided by one of the project partners. We then placed the FPP dome reinforcement on top of that liner with our SAMBA Pro Lab system. The still unhardened prepreg reinforcement was consecutively overwrapped in an industry standard wet winding process, but using an adjusted winding program with those orientation layers omitted that are part of the dome reinforcement. Our project partner performed the filament winding, the subsequent co-consolidation in an oven, and the mechanical testing.

Results: What is special about it?

This demonstrator shows the successful application of the dome reinforcement solution for high-pressure vessels at this  challenging 300bar-class demonstrator

In addition to the general proof-of-concept, this demonstrator also shows:

• Perfect co-consolidation result of prepreg FPP reinforcement and wet winding overwrap
• Little to no undulation of the reinforcement

The fidelity of this design & process was confirmed by successful burst tests of several demonstrators. In particular, the environmental and economic implications of this solution are significant: Applied at scale, the dome reinforcement solution reduces both material consumption and environmental footprint by 15% and more, enabling a broader and more cost-efficient use of hydrogen in mobility applications.

Relevance: Which components are featuring similar challenges?

The results naturally extend their relevance to all other Type IV pressure vessels, with a specific benefit for high pressure H₂ storage tanks. The longer the tank in comparison to its diameter, the higher are the potential benefits. In addition, tanks with higher operating pressure (e.g. 700 bar), featuring thicker fiber laminates and tank walls, benefit disproportionally well from this solution. The reinforcement concept can also be applied to Type III vessels (metallic liner), and to Type V vessels (liner-less).