Tanks in cars question

[pjones]

If the compressed gas was in a liquid state such as Propane or some other type of liquified gas than it would be more of a concern. Scuba tanks only ever contain gas in its vapour form so there is significantly less cause for concern regarding the temperature.

One of the tanks getting damaged in a rear-ended on the other hand would be more of a concern to me. If you've ever seen the end of a tank valve get knocked off than you would understand why some people are raising this as a concern. I like to err on the cautious side and bring the tanks in when the rest of my gear comes in.

A tank filled with 3000 PSI at 70 Deg. F will only be at 3455 PSI when warmed to 150 (Approximate car temp in sun) Deg. F. The temperature in this case would not be my main concern. You may want to check what the burst pressure is on your rupture disk but I am guessing that it is not too close to this. My tank has a rupture disk of 4000 PSI so in this case as long as My car does not reach 246 Deg. F during transportation than I should be fine.

Scuba Tank - Valve Cut

In a commercial world tanks are supposed to be transported in an upright position and chained so they do not fall over. This also stops the tanks from flying around in an accident and having the stem knocked off (when done right).

 

[spectrum]

Unless you have them packed with towels or a blanket they are probably rocking and rolling a little. That will lead to aluminum dust or bruising of any finish they may have.

As far as thermal effects, don't give it a second thought.

I reiterate the concerns about a collision. I would not not be driving with them needlessly. The odds of being in a collision that sheared a valve off are low but not so low that I would totally ignore the possibility. Use common sense. If they will be used again in a day or two leave them be. If diving is a week away, put them in the garage.

Pete

 

[Leadking]

Just rough numbers off a napkin at lunch, but a cylinder that is 3000 psi at 60 degrees F will only be 3230 psi at 100 degrees F.

Since most Aluminum 80's are filled to 3200 - 3300 at the fill station (to allow for cooling), I wouldn't worry.


All the best, James

see Temperature rise and Heat build up inside a parked Car

 

[knowone]

Roll them down the drive. That way when they come to a stop they are stored horizontally and won't fall over. When your husband puts them away he may wish to store them vertically in a corner or against a wall and they probably won't fall over.

 

[fdog]

A nicely done article, Lee, and given the temperatures we experience up here in the desert, I can believe it.

Still, assuming a full fill at 60 degrees F, at 150 degrees F the pressure would be ~3520 psi. This is well below the typical burst disk, set for 40% (4200 psi in this case), and well below the design yield pressure of 7500 psi.

Of course, this doesn't apply to cave fills, 6351 cylinders, 20 foot deco bottles, or, previously abused (or recipient of swear words) cylinders.


All the best, James