Filling LP tanks to high pressure

[BRT]

There are LOTS of people like this and they and their tanks are fine.

This picture trotted out is probably from Europe. They often do not have burst disks. I'm looking at my Inspiration valve and there is no burst disk.

The comments regarding heat are not correct. A "hot" tank is not "10%" more full. At quick look at Guy-Lussac's law will tell you that pressure will double if temperature doubles. Take your 70F tanks and leave them in a 150F trunk and you'll probably lose your burst disk. If you leave a tank with no burst disk in a Nissan Pathfinder that caught fire you should expect the tank to explode. If you fill more modern LP tanks to 3500psi over and over you should expect that they will outlast you unless you let them rust to hell. Just use burst disks.

The pressure doubles if the temperature doubles. So if you go from 15 deg C to 30 deg C the pressure doubles? Sorry, you have to be measuring temperature in Deg Kelvin.

 

[bl6394]

<snip>
The comments regarding heat are not correct. A "hot" tank is not "10%" more full. At quick look at Guy-Lussac's law will tell you that pressure will double if temperature doubles. Take your 70F tanks and leave them in a 150F trunk and you'll probably lose your burst disk. <snip>

Folks - remember that Guy-Lussac's law is dependent upon the absolute temperature (in Kelvin) - not the relative temperature (in Fahrenheit).

e.g. 75 degrees F. is equal to 297 degrees K.

if one was to double the temperature as described above - one would have to raise the temperature of the cylinder to 610 degrees F. If your truck is at 610 degrees F. - a burst cylinder is not your only problem...

Bjorn

PS - and my Faber LP 95's have regularly been filled to 3300 psi. No adverse results as of yet.

 

[victorzamora]

The thing that really convinced me here was going to cave country and seeing the absurd number of LP tanks getting cave fills every single day. There's no way a shop would do that if there were much of a chance of the tanks blowing up or of the tanks needing to be pulled out of service.

 

[berk]

[/COLOR]

I'm sorry if this has been covered before, but I am looking for a definitive answer. I just inherited 2 LP Faber 130s that has the 2400+ symbol on them and the guy told me you could pump these tanks up to 4000psi in "cave" country.

Do you have a dive shop in Michigan close to you that will fill them past 2500?

---------- Post added January 6th, 2014 at 04:56 PM ----------

The pressure doubles if the temperature doubles. So if you go from 15 deg C to 30 deg C the pressure doubles? Sorry, you have to be measuring temperature in Deg Kelvin.

Yes should be obvious since C and F scale different as well. Maybe 10% is the number. I certainly lose a good bit in cold water, but not in proportion to change in F when thinking about iy.

 

[Omisson]

Wow you must miss a lot! Sorry, I've had that picture of the truck for years, don't remember where I got it from but do remember it was caused by a rusted steel tank that exploded. As I posted my only point was to display the power of a scuba tank. The details are irrelevant the damage they can cause is relevant. If it had been an AL tank and not overfilled just think what another 1000psi could do. It seems to me it was a LP72 but I really can't be sure.


View attachment 174910View attachment 174911 Two of these three are AL the one on the right is rusted so steel.

It had nothing to do with a scuba tank but a CO2 class B paintball tank- it was 2010 in Atlanta.

http://www.11alive.com/news/local/story.aspx?storyid=146114&catid=3

 

[halocline]

This thread show once again how much mis-information, misunderstanding, and myth-persistance exists surrounding the handling of scuba tanks.

 

[captain]

It had nothing to do with a scuba tank but a CO2 class B paintball tank- it was 2010 in Atlanta.

CO2 Canister Explodes Inside Hot Pick-Up, Destroys, Damages 7 Vehicles | 11alive.com

Notice it is not the same truck. The one Afterdark posted happened out of the country, I don't remember where, it wasn't recently. As I recall it was a steel 72 with extensive internal rust.

 

[Omisson]

Notice it is not the same truck. The one Afterdark posted happened out of the country, I don't remember where, it wasn't recently. As I recall it was a steel 72 with extensive internal rust.

Ahhh .... internal rust, ie not in hydro or VIP, and not in the continental US... So who knows what if any ratings it had.


Point being a defectively cared for uninspected, untested tank... Yes that's analogous.... NOT!

 

[Griffo]

nevermind

 

[AfterDark]

It had nothing to do with a scuba tank but a CO2 class B paintball tank- it was 2010 in Atlanta.

CO2 Canister Explodes Inside Hot Pick-Up, Destroys, Damages 7 Vehicles | 11alive.com

Stop calling me a lair please. I've had the picture since before 2010. You are mistaken.