Liquid Nitrogen Flask (Dewar)
Nitrogen FlaskA liquid nitrogen flask, known in technical references as a Dewar tank, is a super-insulated, engineered container for the safe storage and transport of liquid nitrogen in the cryogenic phase (very low temperatures). Its double-walled design and the absolute vacuum between its layers keep the evaporation rate of LN2 to a minimum to prevent waste. Lightweight materials combined with a strong body make this equipment a widely used choice for research centers, cell banks and advanced industries.
Factors in choosing a liquid nitrogen flask
When buying a liquid nitrogen flask, the deciding factor is not just the tank’s capacity or volume; the diameter of the opening (neck) plays a decisive role in the daily evaporation rate and how you use it. As a technical rule, the narrower the neck, the lower the nitrogen evaporation and the longer the liquid lasts. Conversely, a wide opening makes it much easier to access canisters and remove laboratory samples, but it raises the daily evaporation rate accordingly and shortens the intervals between refills.
Specifications Table
| Model | Volume (liters) | Neck diameter (mm) | Number of canisters | Lockable lid |
|---|---|---|---|---|
| YDS-6 | 6 | 50 | 6 | Yes |
| YDS-10-50 | 10 | 50 | 6 | Yes |
| YDS-20-50 | 20 | 50 | 6 | Yes |
| YDS-20-80 | 20 | 80 | 6 | Yes |
| YDS-35-50 | 35 | 50 | 6 | Yes |
| YDS-35-80 | 35 | 80 | 6 | Yes |
| YDS-35-125 | 35 | 125 | 6 | No |
| YDS-50-50 | 50 | 50 | No | No |
| YDS-50-80 | 50 | 80 | 6 | Yes |
| YDS-50-125 | 50 | 125 | No | No |
Parts of a liquid nitrogen flask
Each flask consists of several main parts, and the quality of each directly affects the product’s life and performance:
- Shell: the outer layer of the flask, usually white, which holds the flask’s opening.
- Liner: the inner tank, usually made of aluminum, which has good corrosion resistance.
- Interlayer: the vacuum created between the inner and outer tanks to prevent heat transfer.
- Neck canal: a glass-fiber-reinforced plastic section connecting the inner and outer tanks.
- Lock cover: a lockable lid on top of the flask that prevents samples from being removed or excessive evaporation.
Applications
- Laboratory sciences: storage of biological samples, stem cells and tissue at ultra-low temperatures
- Infertility treatment (IVF): storage of sperm, embryos and other temperature-sensitive samples in fertility centers and hospitals
- Skin and hair: cryotherapy applications and cold treatments for skin and hair
- Metallurgy: sampling and cold testing in the metal industry
- Pharmaceuticals: storage of raw materials and temperature-sensitive samples in drug production
- Veterinary: storage and transport of livestock semen
Safety and storage tips
Proper storage of a full liquid nitrogen flask requires keeping the tank in a completely dry, cool, well-ventilated place away from direct sunlight. Since any impact, fall or unsafe handling can cause irreparable damage to the internal vacuum layers and permanently destroy the insulation, it must be transported very carefully; it is also recommended to monitor the remaining contents only with special rulers (dipsticks) or by weighing the tank on digital scales. Finally, to prevent the risk of asphyxiation from falling oxygen levels due to gas evaporation, never use this equipment in enclosed spaces without free air flow.
Guide to choosing the right flask
The key factor in choosing a model is the neck diameter, not just the volume:
- 50 mm neck (maximum holding time): with the lowest daily evaporation, this size is the best choice for archival storage and long-term preservation, when you don’t need to move or remove samples often.
- 80 mm neck (balanced use): an ideal balance between insulation and quick access; designed for laboratories and medical centers that need to access canisters and samples several times a week.
- 125 mm neck (maximum access): this model gives maximum access for biological racks and large canisters. Because of its wide opening, however, it has a higher daily evaporation rate and is only suitable for active daily use, not long-term storage.
Questions to ask yourself before buying:
- How many times a week do you need to access the inside of the flask?
- How wide an opening do your samples/canisters need?
- Will the flask be moved around or kept in one place?
For a more accurate choice, contact Bonyan Gas sales experts, who will recommend the right model based on your type of samples and frequency of use.
A double-walled vacuum vessel for storing liquid nitrogen at −196°C without rapid evaporation.
The tank must always be moved fully upright, secured and in a well-ventilated area (to prevent asphyxiation).
If not hit hard and stored properly, the vacuum insulation of these tanks can keep its original performance for years.
Flask volume, quality of the vacuum insulation and the resulting evaporation rate and static holding time are the main price factors.
The vacuum between the two walls stops heat transfer by conduction and convection and prevents the nitrogen from boiling and evaporating.
With proper care and no hard impacts, the vacuum insulation keeps its original performance for years; however, its life depends on the model and build quality.