When choosing a cryogenic tank for the long-term storage of biological samples, you are faced with a fundamental decision: stainless steel or aluminum? Both materials have their place in cryogenics, but they differ in key properties that have a direct impact on safety, efficiency and total cost of ownership.
Consarctic® deliberately uses stainless steel for its large storage tanks in the BSD+ and BSF+ series, while the more compact ABV+ and ABS+ containers are made of high-quality aluminum alloys - each material choice with good reasons. In this article, we analyze the advantages and disadvantages of both materials and help you make the right decision for your application.
Austenitic stainless steel is one of the few metals that fully retains its toughness at cryogenic temperatures. Unlike many other steels, which become brittle at low temperatures (low-temperature embrittlement), austenitic stainless steel remains ductile and fracture-resistant even at -196°C.
Aluminum alloys also retain their toughness at low temperatures and are therefore suitable in principle for cryogenic applications.
The insulating performance of a cryogenic tank depends largely on the quality and long-term stability of the vacuum between the inner and outer walls. Stainless steel has a decisive advantage here.
All materials emit a minimum of gases under vacuum conditions (outgassing). However, the outgassing rate of stainless steel is significantly lower than that of aluminum. This means that the vacuum in a stainless steel tank remains more stable over years and decades - and thus the insulation performance and nitrogen consumption also remain consistently low.
A cryogenic tank with a decreasing vacuum consumes more and more nitrogen as the heat input increases. With a stainless steel tank from the BSD+ series from Consarctic® , the daily evaporation loss remains at a low, constant level over the entire service life of the tank - a measurable economic advantage.
In GMP-regulated environments, the cleanability of tank surfaces is an important factor:
Aluminum has clear strengths in applications where weight is a decisive factor:
Stainless steel is the superior choice for large stationary tanks that are in continuous operation for decades:
The question of material is not a question of good or bad - but of suitable or unsuitable for the respective application. Consarctic® deliberately combines both materials in its product portfolio in order to be able to offer the optimum solution for every application.
Not sure which material is ideal for your application? Our material experts will be happy to advise you and help you make a decision based on your specific requirements in terms of capacity, mobility, service life and budget.