The safe and efficient use of hydrogen as an energy source requires innovative technologies and the highest standards. Hydrogen pressure vessels, which have to withstand extreme pressures of up to 1000 bar, play a central role in this. At Hexagon Purus' new production site in Kassel, these containers are intensively tested using a modern testing system from Hegewald & Peschke.
Hexagon Purus is a leading provider of solutions for zero-emission mobility and energy storage. In 2023, the Norwegian company opened a new production site for hydrogen pressure vessels for heavy duty trucks, buses and shipping in Kassel. The wrapped pressure vessels are filled with highly flammable hydrogen and have to withstand extremely high pressures of up to 1000 bar. In order to meet these requirements reliably and safely, the materials from which the containers are made are tested according to strict specifications. The company uses a testing system from Hegewald & Peschke for this purpose.
At the heart of the testing system is the inspekt 100 kN universal testing machine with an extended test chamber height, which offers flexible application options for a wide range of specimen shapes and sizes. 
The integration of a temperature chamber with a wide temperature range from -80°C to +260°C enables the simulation of real operating conditions for the hydrogen containers. Separate access to the test chamber within the temperature chamber allows samples to be changed quickly without interrupting the conditioning process.
This reduces cycle times, lowers operating costs and minimizes ice and condensate formation in cooling mode. The test environment remains stable, which further increases the reproducibility of the results.
The video extensometer used offers a non-contact measurement solution that also determines stable and accurate strain values when testing inside the temperature chamber.
Depending on the test method, different tools are used for specimen gripping, which can be changed quickly and easily using standardized adapters
For tensile tests, a pneumatic wedge type grip with specimen depth stops enables safe and repeatable clamping of the specimens, even under temperature control conditions. Tensile tests are performed on plastic specimens in accordance with DIN EN ISO 527, ASTM D638 and DVS2033 as well as tensile tests on CFRP specimens (with bonded clamping surfaces) in accordance with DIN EN ISO 527.
A 3-point bending device allows material tests according to ASTM D2344, in particular ILSS tests (Interlaminar Shear Strength). The interlaminar shear strength measures the shear strength between the individual layers of a composite material. The ILSS value indicates how well the layers of a composite material are bonded by the matrix and fibers. A low shear strength indicates potential weaknesses in the laminate structure, such as poor adhesion or material defects.
Particularly in safety-critical applications, such as hydrogen pressure vessels, material testing prevents potential material defects, reduces the risk of failure and extends the service life of the products.
