So, you’re looking to buy some liquid nitrogen. Only trouble is, of course, it’s not exactly a thing you can just pick up from the grocery store and wheel out in a cart. Nitrogen isn’t an illegal substance, of course, and the uses for it are many and varied.
Maybe you’re using it for cooking, for instance? Or for shrink-welding; liquid nitrogen’s cooling properties are great for this sort of thing. You can also use liquid nitrogen as a coolant, although you should be careful with this application because you can easily use too much and cause just as many problems as overheating!
Liquid nitrogen is nitrogen gas at an extremely low temperature. In this state it rests in a liquid form, which is good for transportation since liquid is much more condensed than any gas. It is colorless and kept at a very cold temperature to maintain its chief property: it rapidly freezes all that it comes into contact with, including human flesh. For this reason, it can be considered a dangerous substance similar to something like gasoline or kerosene, although the latter two are more easily-acquired thanks to their widespread use as fuel sources for cars and lights.
Preparation and Cost
Whatever your applications, you can find liquid nitrogen at a few specific places for bulk purchase. It’s very rare that you can just buy a little tube of it, however, so more often than not you’ll need to first make sure that you’ve got an LN2 dewar. LN2 is the chemical abbreviation for liquid nitrogen, by the way, and a dewar is a specific container, usually white, that you store pressurized LN2 in. You’ve probably seen them wheeled around on dollies before because they can get quite heavy. They are built to contain a liquid can keep it cold, not a bunch of gas at room temperature.
The dewars are going to cost more than the nitrogen itself; a good container will easily cost you over a hundred dollars, and depending on how much LN2 you need you might end up having to purchase more than one. You can buy these at hardware or industrial stores, as well as welding shops or machine shops. Keep this extra cost in mind when trying to calculate your liquid nitrogen needs.
As for the nitrogen itself? It’s usually pretty cheap, though it varies depending on the exact place. Usually, though, it sells by the liter for around 30 cents to over a dollar. A good number to calculate for is $1 a liter, so that you’re prepared if it ends up being expensive from wherever you decide to purchase from. It is possible that you might be able to get an extraordinary deal from a mass-producer of liquid nitrogen, particularly if you’re a business that deals with hardware and welding, where the cost per liter of liquid nitrogen drops as low as one cent per liter.
Now that you’ve got your dewars and know how much cash you need for your liquid nitrogen, you need to know where to get it. There are a few places in particular where you’ll find success when trying to buy LN2.
The first option for your nitrogen quest can be those essential stores where mechanical work is already done all day, every day. Tire dealerships can usually be found in every major city in America, and even in a lot of the smaller towns, too, which can be helpful if you need liquid nitrogen at a place more rural than the big city. These dealerships are everywhere because cars are constantly going through tires and requiring maintenance or touch-ups.
You might be wondering why tire dealerships have liquid nitrogen on hand at all. But believe it or not, some dealerships use liquid nitrogen in tires. Sounds crazy, right? But nitrogen actually has a handful of advantages compared to regular oxygen. For instance, nitrogen is far less likely to migrate through your tire than oxygen is, making it ideal for maintaining an even pressure distribution in a tire. Nitrogen also has a bonus quality in that it experiences less pressure change when the temperature shifts. As you might have guessed, your tires’ temperatures can change rapidly when they are moving or staying still, so this is a great quality to have in a tire filler.
Tire dealerships have a lot of this stuff in the same kind of dewars that you’ll need to store your liquid nitrogen in. It is possible that some of them will be able to sell you the full dewars, but no matter what each dealership that has LN2 will be able to fill your own personal dewars at the very least. This is why it’s important to have your own containers: it’s easier to get nitrogen for filling than it is to buy the entire deal, LN2 and container combined.
Costco, the supermarket extraordinaire. I previously mentioned that supermarkets didn’t sell liquid nitrogen, but Costco is a special exception. You will recall that Costco sells just about everything; they have a grocery section, a furniture section, a toy section, an electronics aisle and even a gas station at some of the larger outlets. Those gas stations are what we’re interested in for the most part.
But don’t discount the fact that some Costcos act as hardware stores, too, depending on their customer base and what part of the country they are based in. Some Costcos have liquid nitrogen dewars for sale that you can then take to their gas stations.
Regardless of whether or not they sell dewars, you can always bring your own and fill them at their gas station. Like the tire dealerships before, Costco is starting to use liquid nitrogen to fill tires since nitrogen has a better long-term effect than regular oxygen. This is great for business, since it costs money to put a different substance in the tires, and great for regular drivers since they don’t have to get their tires checked so regularly.
For you, it means you can roll up with your dewars and pay for nitrogen to be sunk strait into your waiting containers. You can usually purchase the nitrogen at the tire center in the store, since it’s not just a normal pump like the other ones for gas. Once you’ve got an employee’s help in setting up, you can even buff up your tires if you like, since you’re already there!
Welding Supply Stores
Our last place is the most industrial and bulk-friendly of the options. Welding supply stores aren’t an outlet for afternoon shopping; they’re serious places for contractors or builders to come and find the tools and supplies they need to complete real, physical labor. A lot of welding supply stores can be found in manufacturing hubs across America, either in cities or more rural locations. These stores might also sell the dewars we talked about earlier, so if you need both and there’s a welding supply store nearby you might be able to come here for everything you need.
Many larger welding supply stores already use liquid nitrogen for their own welding operations; you’ll recall that liquid nitrogen is a key ingredient in shrink-welding. Liquid nitrogen is a fantastic coolant as well, so these stores sell LN2 for these purposes and more.
At welding supply stores, you can find liquid nitrogen for bulk purchases, buying it in large quantities for your own dewars or, with certain stores, buying it as it comes in pre-packaged dewars. This is most common with hardware stores who typically sell to larger shops, mechanical operations or factories which use the LN2 in massive quantities for cooling and welding. These stores can get you as large an amount as you need, though keep in mind that since they are not a factory themselves, they don’t have a practically-infinite amount of the stuff.
It is possible that, if you need so much liquid nitrogen that they can’t fulfill your order, they might be able to requisition more for a longer-term arrangement like those they sometimes make with factories or larger shops. It’s possible you’ll have to pay for most of this cost up front, but it can be more reliable than driving your truck around looking for places to fill your dewars, one tank at a time.
Whatever your needs, liquid nitrogen isn’t quite the elusive substance that it at first appears to be. Since it’s such an industrial substance it simply isn’t offered as easily as a lot of more common products. It also requires a number of preparatory steps that are essential, since liquid nitrogen can be dangerous if not used properly. Wherever you try to buy liquid nitrogen, remember that keeping it cold and away from contact with human skin is important!
But so long as you know where to look you can find what you need and get working on your next project, pronto!