Are these Liquid Nitrogen jackets?

Hi Gang,

I have a 40lb solvent tank with a coil doing down the inside. The coil is connected to the chiller which only goes down to -38C . My tank is jacketed with only one inlet/outlet that looks like this:

Only the solvent tank and dewax column have it. I’m thinking it must be for liquid nitrogen, but there are no instructions or info from the manufacturer on how to use it. There wasn’t even a ball valve on it. I put a Swagelok valve on it so I could draw a vacuum on it and use it as an insulation jacket. Now I am wanting to get colder than -38C. Does anyone have experience with liquid Nitrogen cooling? I’m afraid I will build up pressure in the jacket and pop, but the jacket does have this 3000 psi MAWP what looks like a PRV but I’m not 100% sure what it is. Have you guys seen this before?

Any advice is greatly appreciated!

Look up the part number, that will tell you if it’s a relief valve or check valve (looks more like the latter but I can’t see too well). Also, do not use the PRV setting as a rating that the jacket can take, that could be a “last” mistake.


Yep. Clearly a check valve (arrow with 1/3 PSI gives it away).

==> it’s a vacuum jacket.

And does not require the ball valve to work as such…

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Please make sure you do not put liquid nitrogen into the annular space without a vent/relief. Liquid Nitrogen expands as it evaporates and could cause the tank to rupture.

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#^>?€^. Deleted.

Forgot we were looking at only a single penetration on that jacket…