A liquid nitrogen (LN2) storage tank, or dewar, is a vacuum-insulated vessel that keeps liquid nitrogen at roughly ‑196°C for days or weeks with minimal loss. Whether you're running cryosurgery, preserving biological samples, or supplying a lab process, choosing the right dewar comes down to how much LN2 you use, how long it must last between refills, and how you'll draw it out.
Storage vs. working dewars
Not all dewars do the same job. Storage (static) dewars are optimized to hold liquid nitrogen as long as possible with the slowest evaporation — ideal for maintaining a supply. Working dewars and containers are designed for frequent access and pouring or withdrawal. Some tanks store samples in the vapor or liquid phase for biological preservation. Identify your use case first.
Key factors to consider
- Capacity: Sized in liters, from small portable dewars to large stationary tanks. Match capacity to your consumption and delivery schedule — bigger means fewer refills but more weight and footprint.
- Static hold time / evaporation rate: The normal evaporation rate (NER) tells you how fast LN2 is lost when idle, which sets how long a fill lasts. Lower loss means longer hold time.
- Neck opening: A narrow neck slows evaporation and extends hold time; a wider neck gives easier access for samples or withdrawal devices. It's a trade-off between efficiency and convenience.
- Withdrawal method: If you'll dispense LN2 (for example, to fill a cryosurgical sprayer), plan for a withdrawal device, transfer hose, or roller base for larger tanks.
- Construction and mobility: Durable aluminum construction, protective collars, and optional roller bases make handling safer and easier.
Safety first
Liquid nitrogen displaces oxygen as it evaporates, so always store and use dewars in well-ventilated areas, never in sealed rooms or unventilated vehicles. Use insulated cryo-gloves and a face shield when handling, keep the vessel upright, and never seal a dewar in a way that blocks pressure relief.
Explore our Liquid Nitrogen Storage Tanks & Flasks and LN2 tanks with discharge equipment, plus supporting cryogenic accessories, to find the right storage for your workflow.