Any problem leaving a filled tank in the car?

[Bob DBF]

A faulty disk is more likely to fail at 3900 than at 3000

All kidding aside, you do bring up a good point--faulty burst disks. I'm not sure how often you should have the burst disk replaced. Once a year seems too often. Is it OK to have it replaced and the valve rebuilt only when the tank is in for hydro?
Hopefully someone will chime in with the answer.

Ron

I replace at hydro, when rebuilding the valve, or when switching valves around between tanks (don't ask). Never had a burst disc rupture on my tanks and that includes a couple of unintended overfills.



Bob
----------------------
I may be old, but I’m not dead yet.

 

[Guba]

I agree with the mathmatics provided, but when I researched out what the pressure tolerance of scuba burst discs was, the literature said "125-166 percent of working pressure". That translates to about 3750 psi to 4980 psi. That's quite a range, but the lower end is just under the pressure generated in the given example. Someone who has more experience filling tanks will probably be able to provide better information about the capacity of the discs.

 

[Peter_C]

I've left mine in the car for a week during the summer once. They were hot as hell when I finally did move them, but they hadn't blown up.

Downside was, after expansion and contraction from the change in temps, both tanks had only 2400.

So just where did the air go, as it either leaked out, or can you say short fill? What is hot? Too hot to touch? Or just hot enough that it kinda hurts? Personally I consider hot anything I can not touch. From somone who can hold something much hotter than most other people...well it still isn't that hot as far as metals go.

We have a similar question usually from students.

Will the air freeze?

Oh that is a good one. Do you give them the answer of YES, at around 55*k?

I had a burst disk let go on my reg testing stand. It went somewhere around 4,000psi as I cranked up the pressure to test my regs. It was rated at 3,000 psi. Whoops! I replaced it promtly with a higher pressure disk, as I test my regs at their rated pressure of 4,200 psi.

 

[j yaeger]

will the air in the tank freeze???
no,but any moisture sure will!!!!
and it WILL help your regs to freeflow in cold water!!!!!
makes the inside of your steelies nice and brown too!!!!!
burst disc replace after new hydro-cheapo insurance!
don't fill your al 80 to 3300.....unless it's rated 3300...!!!!!!
that's more important than leaving the darn things in the car!!!
my 2c
have fun
yaeg

 

[NAM001]

butst disks are supposed to burst tat no less than 90% of test presure. so a 3k tank tests at 5/3 or 5k and the burst disk blows between 4500 and 5k

I agree with the mathmatics provided, but when I researched out what the pressure tolerance of scuba burst discs was, the literature said "125-166 percent of working pressure". That translates to about 3750 psi to 4980 psi. That's quite a range, but the lower end is just under the pressure generated in the given example. Someone who has more experience filling tanks will probably be able to provide better information about the capacity of the discs.

 

[NAM001]

part of the vis is a valve check including that the burst disk is correct for the tank and valve and the burst relief bolt is multi ported so each year it is supposed to be checked or replaced. does it happen no.

A faulty disk is more likely to fail at 3900 than at 3000

All kidding aside, you do bring up a good point--faulty burst disks. I'm not sure how often you should have the burst disk replaced. Once a year seems too often. Is it OK to have it replaced and the valve rebuilt only when the tank is in for hydro?
Hopefully someone will chime in with the answer.

Ron

 

[Superlyte27]

Someone please do the math. I'm in Florida, so lets say worse case scenario. I fill my AL80 to 3000PSI. I measure my tank temperature with a laser and record 102 degrees after filling (and that's the outside of the tank, in reality the inside is warmer). I leave the tanks in my trunk and the temperature in the trunk increases to 150 degrees. What is the pressure in the tanks???


EDIT
LOL< by the time i got this typed out, someone had beaten me to it, and their math was better

 

[Superlyte27]

I still gotta go on the other side of the argument from most of the posters, but perhaps my opinion is based on false assumptions.

I have always been told that a tank has a limited number of fills before it will fail hydro due to the expansion and contraction. If you leave a full tank in a car where the temperature drops at night and heats up considerably in the sun the next day, then I think you are reducing the life of your tank.

Back before the DOT made them pull the advertisement, faber used to claim 10,000 fills at 4000psi. You're probably right, there is probably a number of limited fills before a tank fails hydro, but you'll never make that number of dives on a particular tank.

 

[Superlyte27]

A faulty disk is more likely to fail at 3900 than at 3000

All kidding aside, you do bring up a good point--faulty burst disks. I'm not sure how often you should have the burst disk replaced. Once a year seems too often. Is it OK to have it replaced and the valve rebuilt only when the tank is in for hydro?
Hopefully someone will chime in with the answer.

Ron

I've been replacing mine at hydro. I've never had a failure. With that said, i'll probably have one this week.