Storing steel tanks in sub zero garage

[tmassey]

Dewpoint changes with pressure. I didn't do the calculations myself, but this site Dew point under pressure | Airpack, custom made oil and gas packages world wide lets you calculate it and indicates that air with an uncompressed dewpoint of -50 F (-45 C) has a dewpoint of 12 C at 200 bar. Do you think this is incorrect?

Great point. You are 100% right.

Like others said, this is the maximum. My compressor’s last test had a dew point of -74F. That calculates to be 15F at 230 bar. We get below 15F (not this year...). Hmm.............

Thank you for bringing this up!

I can say practically I’ve never had a problem: I’ve done this for 10 years in Michigan. My tanks were tumbled exactly once — after a hydro. Having said that: I’m dropping the pressure in my tanks! That’s way easier than dragging multiple sets of doubles down into the basement — and back *up* out of the basement...

 

[Steve_C]

Unheated garage that is attached to a house is usually above ambient temperature. For fun I have been noting the temp my car shows before and after leaving the garage. (I am now in NC but it gets cool)

I used to live in Minnesota and we had an unheated garage under the house, about half exposed. We would keep a bucket of minnows there all winter for ice fishing and it would never freeze.

 

[vjb.knife]

The dew point calculation does not take into account the fact that Scuba compressors dry the air as it is being compressed. You need to get a VIP every year and any problems would be detected, but it will not be an issue.