Empty tank storage procedure?

[uncfnp]

3ft in October
....
What do you do in January?

I'm planning to store myself some place more thermally regulated (Cozumel) this winter

 

[2airishuman]

Fill to 300 psi, let sit, dump, repeat, let sit with valve closed until spring

 

[guruboy]

actually, wouldn't it be better to seal it while cold, and then move to a warmer storage area?

cold air holds less moisture.

 

[tbone1004]

actually, wouldn't it be better to seal it while cold, and then move to a warmer storage area?

cold air holds less moisture.

yes and no. The humidity of air around a wood stove is basically like the desert which is why you see most people that have wood stoves, also have some sort of humidifier around them

 

[guruboy]

Maybe it's dry because they are heating up winter air, which is cold and dry to begin with.

 

[northernone]

I'm puzzling through this idea. Here's a few things.

Wood heat produces "dry air" because it's a ventilation system drawing in the cold dry air from outside and when heating it the relative humidity is reduced. Warm air can hold more moisture, and the cold air drawn into the house contains much less moisture. Fun fact, without adequate ventilation a wood stove makes the house hypoxic.

When I bring a cold metal block in next to the stove that dry warm air will cool against it. Cold enough to reach dew point as now the relative humidity quickly raises. Meaning that dry warm air will cover my cylinder inside and out with water droplets.

The kettle on the stovetop for tea puts a little moisture back into the air so the walls don't crack, doors don't warp and my guitar doesn't go out of tune so badly in the winter. Unfortunately my cylinders don't like condensed tea and take days to dry inside after the mist bath of condensation.

I've enjoyed thinking through this. Thank you guys for the food for thought and suggestions.

Cameron

 

[Akimbo]

For the totally anal reading this, fill to several atmospheres and dump a few cycles with oxygen-free gas derived from a cryogenic source.

Technical Sidebar:
The vast majority of industrial through medical-grade Oxygen, Nitrogen, and Argon is produced by compressing and refrigerating air into a liquid (cryogenic). The liquid air is then warmed in a controlled manner where each gas vaporizes at different temperatures producing ultra high purity and totally dry gasses. We purged critical instrument and CCTV housings on deep submersibles and ROVs (Remote Operated Vehicles) with pure Nitrogen since moisture on lenses and electronics would cause very expensive mission failures.

 

[wedivebc]

I just found a tank that has never been filled since last hydro. It is now due for another but it still has the plastic dust plug from the last one. Looked inside and it's still shiny and new even though it was tucked in the back of an unheated garage over 5 west coast Canadian winters.

 

[northernone]

For the totally anal reading this, fill to several atmospheres and dump a few cycles with oxygen-free gas derived from a cryogenic source.

Technical Sidebar:
The vast majority of industrial through medical-grade Oxygen, Nitrogen, and Argon is produced by compressing and refrigerating air into a liquid (cryogenic). The liquid air is then warmed in a controlled manner where each gas vaporizes at different temperatures producing ultra high purity and totally dry gasses. We purged critical instrument and CCTV housings on deep submersibles and ROVs (Remote Operated Vehicles) with pure Nitrogen since moisture on lenses and electronics would cause very expensive mission failures.

Even the mildly posterior retentive amongst us find this an interesting sidebar!

I just found a tank that has never been filled since last hydro. It is now due for another but it still has the plastic dust plug from the last one. Looked inside and it's still shiny and new even though it was tucked in the back of an unheated garage over 5 west coast Canadian winters.

That's excellent news! Thank you.

 

[Akimbo]

Even the mildly posterior retentive amongst us find this an interesting sidebar!

It just occured to me that a few warnings might be in order.

• Be sure to dump the Nitrogen before refilling with air, Nitrox, or Trimix since the mix would be changed
• A lot of people have access to Liquid Nitrogen at work. Tempting as it might be, pouring a small amount into a Scuba cylinder for storage and screwing the valve back on might be ill-advised. I'm not sure if the spot cooling could compromise the metallurgy. Liquid nitrogen vaporizes at -196° C or -321° F at 1 ATA.

Liquid nitrogen is fun, and potentially dangerous, stuff. Every high school physics class should have some to play with.