This would be what we called a "gas pack" - which I think was a brand name, it's been a while.

What I would have considered a 'dewer' was a vessel meant to hold cryogenic liquid that was not under pressure, basically a thermos of any number of sizes. And then there are these large vessels that can hold pressure. Some are only meant to have minimal pressure, because the user is interested in the cryogenic liquid inside, so the pressure is like less than 20psi if memory serves. The unit that is being referred to in this post was the aforementioned 'gas pack' that has an extra set of tubing that is wrapped in a around the inner of two vessels, so that liquid can gasify due to the heat exchange effect this coil provides, and allow this gas to be used by the customer. These are usually vented around 250psi, again if memory serves, so that the vessel doesn't explode, ha ha. You can keep it from venting by isolating this gasification line, but that also reduces the convenience. It'd probably be best to store the vessel in a temperature controlled location to minimize the the chance of overpressurization.

I'm bored at work, if you couldn't tell.