Cryogenic Dewar Tank
DSW International produces liquid cylinders and cryogenic and cryogenic dewar tanks available in various volume capacities to safely contain liquid gas such as argon, carbon dioxide, nitrogen and oxygen.
These liquid gases must be stored at extremely low temperatures to maintain an ideal liquid state and pressure.
cryogenic storage dewar
A cryogenic storage dewar is a specialised type of vacuum flask used for storing cryogens, including liquid nitrogen or liquid helium, which is used to store clinical or research samples at -150°C.
A vacuum between the walls is an insulator, preventing heat transfer and evaporation. It can be made of stainless steel or carbon shells.
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Cryogenic Dewar Tank Inspection
According to the technical requirements of storage tanks, welding seams must be tested with 100% RT (non-destructive) and penetrant test (PT).
High-purity nitrogen (up to 99.999%) will be used to conduct the strength testing.
Finally, advanced helium mass spectrometer leak detectors (with precision up to 2×10-9Pa.L/s) will be used to conduct Helium mass spectrometer leak detection.
The inner containers of the storage tanks will be passivated by overall pickling to meet the cleanliness requirements for dangerous goods.
Imported ultraviolet black light lamps will ensure no oil stains and other organic impurities in the inner containers.
The inner and outer containers, after cleaning, will be assembled at a time interval of less than 2.5 hours.
After assembling, the inner containers and interlayers will be filled with nitrogen to protect them from dust and organic impurities so as to ensure cleanliness.
The inner and outer surfaces of the outer containers will be subject to overall sandblasting treatment to meet the requirements of the Sa-2.5 standard.
When the surfaces of steel plates show a metallic colour, a vacuum cleaner will be used to suck off the dust adhered to the surface so as to ensure the vacuum degree in the interlayer further.
Special high-quality perlite is used as the insulation material in the interlayer.
The perlite will be treated using our company’s unique process before being in the interlayer.
After being manufactured, all the internal cylinders of the welded Insulated container will be subject to gas-tight and pressure performance tests.
The internal and outer cylinders will be subject to rigorous Helium mass spectrum leak detection.
After the production, all the pipe openings will be opened to carry out nitrogen purging and replacement to meet the oxygen usage standard.
After this, all the pipelines and valves will be sealed, and the tanks will be filled with 0.2MPa high-purity nitrogen to protect them.
