Quote Originally Posted by lesstutrey View Post
Since most places require you to use a truck to haul the dewar home (i have a van and station wagon), i'm planning on going through a company i used to work with when i did HVAC because they'll drop it off at my house or let me take it home in my van, whereas no one else will do that for me due to insurance reasons. However they are telling me i need some sort of certification on my dewar (i guess aside from DOT) to make sure it's still in proper working order. They also haven't told me where to go to do it. I assumed the gas company would do the testing.. The company that's given me the lowest quote so far (125$ for 80L) looked at pics of my dewar and said it's cool, they just need to hold it for 24 hours to do a cool down (something i thought they only did for LHe, but my dewar has been in storage for at least a year, and still holds some degree of fluid according to meter no biggie) and then i can pick it up the next day full, if i had a truck. Any of you have any idea what they are talking about for certification? Isn't that testing done by suppliers? I have a tank of nitrogen for my MIG and i can pressure test the thing, though i know it doens't leak. Dewar can be seen in my sig.
Mine has a DOT tag on it. I am not sure what they are talking about a cool down, your Dewar is not that much bigger than mine at 50L.

Yes they do cool downs on LHe Dewars but not really necessory on the size Dewars we use.

Reason they might want to do a cool down is so they do not waste so much LN2 to start filling it up, a fair amount can used in this process I guess.

Well they pick it up and return ir for you ?
I know airgas will if you have your own Dewars, the big ones that is.

I guess, worst case, just send it over to me and I will take it off your hands