A valve box is an advanced application mainly used to control liquid helium or liquid hydrogen systems. This equipment is integrated into the valve box to avoid excess valves, sensors, and extra equipment installed around a vacuum insulated pipe.
A valve box, like the vacuum insulated pipe itself, is fitted with supreme insulation. Liquid hydrogen has a temperature of -252.9 °C and liquid helium as low as -268.9 °C. These cryogenic liquids are both still highly scarce and expensive.
It is therefore essential to prevent the warming up and consequent loss of this liquid gas.
Combining all the necessary equipment in one valve box has several advantages. It allows the vacuum insulated piping (especially the MTL) to be designed and manufactured much more easily. A central control system controls the valve box. The result is a well-organized and user-friendly unit.
A valve box is a large vacuum insulated container with an outer wall of stainless steel (304 (L), 321, or 316 (L)). For additional insulation, a copper radiation shield is placed inside the box; this shield is dynamically cooled with return gas or liquid nitrogen. Multi-layer insulation consisting of glass and aluminum or Mylar is also used.
A typical valve box for liquid helium or liquid hydrogen contains the following components:
- Open/close valves
- Control valves
- Safety valves
- Temperature sensors
- Pressure sensors
- Flow meters
- Level controllers
- Phase separators
- Heat Exchangers
Valve boxes are always developed in close consultation with our customers. Together, we assess the specific requirements of the infrastructure and application, thus designing a perfectly fitting valve box.
Liquid helium is mainly used in scientific research and the medical industry. The cryogenic liquid is, for instance, used to cool superconducting magnets in particle accelerators and MRI scanners.
Liquid hydrogen takes an increasingly important position in the energy transition. In particular, the mobility market for trucks, aircraft, and ships are leading the way in the application of liquid hydrogen.
Valve boxes are therefore primarily found in these industries. Together with our vacuum insulated piping and MTL, these boxes ensure that liquid helium and liquid hydrogen reach the applications safely and in optimum quality.
For more on our liquid hydrogen projects, continue reading on our Demaco Hydrogen page.