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Liquid Nitrogen Dewars

Liquid Nitrogen Dewars

These Dewars are designed for storing and dispensing small quantities of liquid nitrogen. Easy to operate, the snap on cap and necktube core assure positive closure and easy access without unnecessary exposures to the cryogen. Constructed from materials of the highest performance and quality including an aluminum exterior, these containers are not only rugged, robust, and dependable, but also have very high thermal efficiencies. When using liquid nitrogen, be sure to use the highest quality cryo-gloves that can be found anywhere. And for those wanting to keep prepared in the event of a surprise visit by the safety committee, don't forget the often overlooked fact that there is an MSDS for liquid nitrogen. While liquid nitrogen is often times belittled in terms of its real hazards, no mistake should be made about it, one can sustain very serious injuries if not handled properly. Before using any dewar, be it purchased from SPI Supplies or elsewhere, make sure you are familiar with the guidelines and recommendations for safe handling. We also call particular attention to the unique liquid nitrogen withdrawal devices available as an accessory item.

Other safety issues when using liquid nitrogen:

We have been told by safety experts that nitrogen, as inert as it is, causes more fatalities than any other chemical in the laboratory. When someone is encased in a purely nitrogen atmosphere, oxygen flow is reversed from arterial blood and tissues back into the lungs and loss of consciousness follows within seconds. We have heard of incidents at plants, for example one individual was working on top of a reactor, leaned over, got a blast of pure nitrogen, and pitched forward into the vessel unconscious.

In the laboratory, a similar event can occur when working with liquid nitrogen since the cold vapor concentrates at floor level, and a technician leaning down into this cloud can be overcome. Another too common mistake is to ride on a freight elevator with the container when transporting liquid nitrogen between floors (elevators should have warning signs posted to strictly prohibit this practice). The staff must also be trained to overcome their natural instinct to rush to assist an unconscious coworker since over half of workers who die in confined spaces are attempting to rescue other workers. Since nitrogen constitutes about 78% of the air that we breathe, it is easy to become complacent and to underestimate its dangers. If you use nitrogen in your lab, safe handling of this dangerous gas should be an annual topic for a safety meeting to remind the staff of the risks.

Construction of the dewars offered by SPI Supplies:

These dewars are of all metal construction and are glass-free. Those dewars that contain glass are much more fragile and less robust than the dewars described on this webpage.

The inspiration for the proceeding two paragraphs came from a list server posting from the Analytical Laboratory Manager's Association (ALMA).

Pressurized vs. Non-pressurized Dewars:

Always remember that there are two different ways to store liquid nitrogen. First, there are dewars of the type described on this page, which are vessels that are open to the atmosphere so that the liquid nitrogen becomes a boiling liquid at a pressure of one atmosphere. The other, a pressurized dewar and of a type that is not offered by SPI Supplies, is a closed vessel, where liquid nitrogen becomes a boiling liquid at a temperature determined by the pressure within the vessel. This type of dewar is regulated as pressure vessels, because there is the potential for a substantial pressure to develop within them, and generally they are protected by a pressure relief valve.

One should note however that there is no need to utilize a pressurized vessel for the local moving of the liquid, such as from the master supply tank (or dewar) to some laboratory application.

Also, we should point out that we do offer a liquid nitrogen withdrawal device that allows the boiling liquid to create a small pressure in the dewar, forcing liquid out through a tube; the amount of pressure buildup being controlled by safety valves.

Liquid Nitrogen Refrigerators:

A liquid nitrogen refrigerator is a device more for storing refrigerated samples than a transfer dewar. A refrigerator should not be confused with a liquid nitrogen transfer dewar!

Not for on-the-road use:

These dewars are designed, engineered, and manufactured for the transportation and storage of liquid nitrogen within a laboratory facility. They are not designed for shipment of liquid nitrogen or for transportation in a closed vehicle on the road from one location to another. USA customers should note that they do not have a Department of Transportation (USDOT) number.

Special note to customers with liquid nitrogen cooled detectors on an SEM or TEM:

When there is the need to know more about beam penetration and interaction with your samples, try out the Electron Flight Simulator™. It has been highly useful in terms of modeling the electron interactions that are actually occurring in real samples.

Special note about the "top":

The dewars (except for the 4 liter size) come with a standard lid, also called the "neck tube core". It is both a mechanical cover for the opening and an insulating cover for the top of the dewar, but it is loose enough for the nitrogen to be able to boil away without pressure buildup. The small 4 liter dewar comes with what is called a "cap". So it is not necessary to purchase an additional one. However, often times customers prefer to order spare neck tube cores or caps because they modify them so that different kinds of samples can be suspended into the dewar and kept at cryo temperatures.

Safety Considerations:

Be sure you review the MSDS information before using liquid nitrogen. This is a potential very hazardous material, yet often times it is not given the respect it deserves. We believe that risk is greatly reduced and minimized if cryo gloves are used when handling liquid nitrogen.

We also believe that open faced or canvas type shoes should not be worn when working with liquid nitrogen. Often times we hear hypothetical scenarios meant to describe situations where the wearing of canvas (or even open faced) shoes would be safe. But we believe it is much like the argument about automobile seat belts: One can make a sport out of creating scenarios where one might be safer in an accident not wearing seatbelts, but if you want the statistics to be on your side, then you would be wise to wear a seat belt. We believe that the same would be true for the wearing of non-canvas and non-open-faced shoes, and indeed the best choice of shoes would be OSHA approved safety shoes.

Liquid Withdrawal Device

The smallest dewar for which we offer a liquid withdrawal device would be the one with capacity 25 liters as described below.

There are some technical issues surrounding the use of transfer devices on the smaller dewars, and most customers prefer to hand decant. With the heavier dewars, however, hand decanting is not an option, and the liquid transfer device becomes essential. This is one area where one should not seek to economize when purchasing one of the 25 liter or larger dewars.

Please note the recent maintenance advisory issued by Taylor Wharton for the pressure relief valves on these units.

Recommended Vacuum Grease:

When using the dewars as a "refrigerator" or when the need arises for other reasons, we recommend Apiezon® N Cryogenic High Vacuum Grease, which is both silicone and halogen free.

Liquid Capacity Height Diameter Neck Weight Evaporation SPI# Each In Stock
Liters (in.) (in.) Dia. (in.) Empty
(lbs.)
Full
(lbs.)
Loss
(Liters/Day)
4 16.7 7.6 1.2 6.0 13.0 0.4 10415-AB$709.17 Add to cartYes
5 17.5 7.6 5.6 5.0 14.0 0.77 10416-AB701.09 Add to cartYes
10
Not eligible for flat rate shipping programs
21.0 11.4 2.0 13.4 31.2 0.22 10426-AB736.89 Add to cartYes
25
Not eligible for flat rate shipping programs
25.7 15.6 2.5 26.4 71.0 0.23 10418-AB1,007.16 Add to cartYes
35
Not eligible for flat rate shipping programs
25.6 18.8 2.5 28.0 90.0 0.23 10419-AB1,178.10 Add to cartYes
50
Not eligible for flat rate shipping programs
32.6 18.8 2.5 38.9 128.0 0.41 10420-AB1,565.03 Add to cartNo

Accessories

Description SPI# Each In Stock
Spare caps
4 liter dewar (only size available) 10415C-AB18.48 Add to cartYes

Necktube Cores Liquid Nitrogen Dewars
5 liter dewar 10416N-AB43.89 Add to cartYes
10 10426N-AB43.89 Add to cartYes
25 10418N-AB51.98 Add to cartYes
35 and 50 10419/20N-AB51.98 Add to cartYes

Roller Bases Liquid Nitrogen Dewars
25 liter dewar 10418R-AB265.65 Add to cartYes
35 and 50 10419/20R-AB271.43 Add to cartNo

Liquid Withdrawal Device Liquid Nitrogen Dewars
25, 35 and 50 10418WD-AB907.83 Add to cartYes

Tipping Stand Liquid Nitrogen Dewars
25 liter dewars only 10418T-AB1,041.81 Add to cartYes
Cryogenic Refrigerator
Not eligible for flat rate shipping programs
10421-AB3,089.63 Add to cartNo Liquid Nitrogen Dewars