The use case
We had already delivered the first valves to the company in 1986 for an industrial H2 thermoprocessing application. Or more accurately: safety shut-off valves for the safe use of hydrogen in the production of fumed silica.
Several combinations of valves comprising two main valves with electric-pneumatic actuator which are closed when unpowered and a vent valve with solenoid actuator which is open when unpowered were used here. Type tested, of course. We delivered eight valve combinations for commissioning in 1986. Further stages of expansion, consisting of two valve combinations each, then followed in 1997, 2001 and 2002.
The challenge
It was expected that the individual valve components would absorb hydrogen over time owing to the long-term operation – starting with the pressure-retaining valve housing, followed by the pressure-retaining spacer and valve spindle, and finally the spindle guide.
The solution
Comprehensive testing of the components was conducted. Most recently in 2021. We removed two valves from the first delivery in 1986 for component analysis during this testing and provided the customer with new valves free of charge. The valve components we removed which were in contact with H2 were tested for changes to the material structure and properties at a Dakks-accredited material testing laboratory.
The result
The analysis from the accredited testing laboratory showed that although the valve components had absorbed H2, they were still fully operational after 37 years. They showed no operational changes in structure. A proper microstructure without abnormalities was verified. And the hardness values and tensile strengths also complied with the standards.
Summary
The case study illustrates our many years of expertise in the field of hydrogen applications on the one hand, and on the other it also highlights the quality, safety and long service life of our products. Hydrogen is simply our profession – and it has been for more than 30 years.
