Propane tank danger?

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
User avatar
Spitfire
Specialist 2
Specialist 2
Posts: 202
Joined: Fri Nov 16, 2007 5:34 am
Location: South Africa

Tue Mar 18, 2008 8:00 am

I dont know how to phrase the question so im just going to say it straight.

Is there any possibility, even a minute chance, of a propane tank explodeing? During combustion or the likes?

My parents said i cant use my Fuel meter unless this question is answer(Why cant i spell today?)

Thanks
P
User avatar
Carlman
Staff Sergeant 2
Staff Sergeant 2
Posts: 1618
Joined: Sat Nov 24, 2007 1:18 am
Location: Western Australia
Been thanked: 2 times

Tue Mar 18, 2008 8:07 am

no under normal circumstances.

ur meter is closed to the tank when firing or combusting takes place so the flame front cannot physically reach it.
Image
Aussie spudders unite!!
User avatar
D_Hall
Staff Sergeant 5
Staff Sergeant 5
United States of America
Posts: 1914
Joined: Thu Feb 07, 2008 7:37 pm
Location: SoCal
Has thanked: 7 times
Been thanked: 41 times

Donating Members

Tue Mar 18, 2008 8:14 am

Spitfire wrote:Is there any possibility, even a minute chance, of a propane tank explodeing? During combustion or the likes?
Anytime you have energetic materials there's a chance of something going wrong. Obviously, a tank of propane is much more likely to explode than a chunk of concrete is.

But how likely is "much more likely?"

Not very.

Put it this way... You could just as easily ask your parents if there is any possibility, even a minute chance, of the gas tank on the family car exploding.... Whatever those odds are, the propane tank exploding is going to be ever so slightly higher, but not much.
User avatar
bigbob12345
Staff Sergeant
Staff Sergeant
Posts: 1516
Joined: Sat Dec 01, 2007 9:13 am
Location: Mercer Island,Washington

Tue Mar 18, 2008 8:42 am

there is no way it will explode.
the propane in there is at a way to high propane to air ratio and will never ignite.
but if there is some fluke and it is at an ignitable fuel air mix then the combustion of it will produce less pressure than the propane in the tank which i believe is 120psi.
to sum it up for you
it cant ignite
and if it does ignite(which it wont) it will not explode because the combustion will produce a max of 75 psi(probably closer to 60psi) and the propane in the tank is pressureized to 120psi when you first get it so it wil not explode
User avatar
Ragnarok
Captain
Captain
Posts: 5401
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK

Tue Mar 18, 2008 8:45 am

Spitfire wrote:I dont know how to phrase the question so im just going to say it straight.
Is there any possibility, even a minute chance, of a propane tank explodeing? During combustion or the likes?
My parents said i cant use my Fuel meter unless this question is answer(Why cant i spell today?)
There is a minute chance. For example, if... your house were on fire, and this propane tank were in the middle of it, then it might heat the propane to the extent the tank might rupture, then the ex-contents would "explode" - or more likely, rapidly combust, rather than actually explode.

If the concern is about flames "tracing back" past two ball valves, through a fuel mix so rich it can't support combustion, then causing the contents of an LPG tank (with no air in it for the fuel to react with) to catch fire, and burst the tank that way...
... as far as you need to worry, there is next to no chance that will happen.
Firstly, flames will be unable to enter the tank.
Secondly, the fuel inside the tank can't burn, there's no air in there.
Thirdly, Air couldn't enter the tank
Fourthly, the tank would be strong enough to withstand any combustion of the fuel, even if it could happen.

I'm going to throw caution to the wind, and go against D_Hall (even if he is an experienced engineer, and I'm only part way through trying to become an engineer), and say that the propane tank is probably less likely to be a threat than a car's fuel tank. There's no air to react with, and the LPG tank is actually designed to take pressure.

In other - stupider - terms: There is a minute chance, but under these circumstances, it's a bit like being worried about the fact that there's a slightly long blade of grass in your lawn that prevents it from being perfect, but ignoring the fact that a dump truck has just pulled up and deposited several tonnes of elephant dung on that same lawn by mistake.

In the list of things that are likely to cause you injury, "exploding propane tank" ranks around the same level as "getting hit by meteorite."
Does that thing kinda look like a big cat to you?
TurboSuper
Corporal 5
Corporal 5
Posts: 986
Joined: Thu Jun 16, 2005 1:44 pm
Been thanked: 1 time

Tue Mar 18, 2008 8:48 am

I always answer this: Does the flame go back into the propane tank when you use it as a torch?


Same idea.
"If at first you dont succeed, then skydiving is not for you" - Darwin Awards
User avatar
Spitfire
Specialist 2
Specialist 2
Posts: 202
Joined: Fri Nov 16, 2007 5:34 am
Location: South Africa

Tue Mar 18, 2008 8:49 am

Thanks for the replys.

Now i can use it. And I learnt something.
TurboSuper
Corporal 5
Corporal 5
Posts: 986
Joined: Thu Jun 16, 2005 1:44 pm
Been thanked: 1 time

Tue Mar 18, 2008 8:49 am

Stupid delay made be double post :?
"If at first you dont succeed, then skydiving is not for you" - Darwin Awards
User avatar
D_Hall
Staff Sergeant 5
Staff Sergeant 5
United States of America
Posts: 1914
Joined: Thu Feb 07, 2008 7:37 pm
Location: SoCal
Has thanked: 7 times
Been thanked: 41 times

Donating Members

Tue Mar 18, 2008 9:47 am

Ragnarok wrote:I'm going to throw caution to the wind, and go against D_Hall (even if he is an experienced engineer, and I'm only part way through trying to become an engineer), and say that the propane tank is probably less likely to be a threat than a car's fuel tank. There's no air to react with, and the LPG tank is actually designed to take pressure.
Well, my "increased likelihood" is based on propane being stored under pressure. IE, I see a greater chance for a simple pressure vessel failure. Tanks rust. The disposable tanks are thin (punctures?). Yada yada yada.

a bit like being worried about the fact that there's a slightly long blade of grass in your lawn that prevents it from being perfect, but ignoring the fact that a dump truck has just pulled up and deposited several tonnes of elephant dung on that same lawn by mistake.
Hey, elephant dung is a great fertilizer! :D
User avatar
DYI
First Sergeant 5
First Sergeant 5
Antigua & Barbuda
Posts: 2862
Joined: Sat Jul 07, 2007 8:18 pm
Location: Here and there

Wed Mar 19, 2008 4:45 pm

I'd say that a propane tank failing in some way is more likely than getting hit by a meteorite, but, as D_Hall said, it would be the "simple pressure vessel failure" route, not the "ignition->rupture->enormous fireball" route.
Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
SpudFarm
First Sergeant 3
First Sergeant 3
Posts: 2571
Joined: Sat Nov 04, 2006 9:39 am
Location: Norway Trondheim area

Donating Members

Wed Mar 19, 2008 5:03 pm

and if it ignites there is a safety valve on them...
"Made in France"
- A spud gun insurance.
User avatar
Spitfire
Specialist 2
Specialist 2
Posts: 202
Joined: Fri Nov 16, 2007 5:34 am
Location: South Africa

Thu Mar 20, 2008 6:47 am

Thanks now i may go out and get the adapter for the tank
User avatar
Lentamentalisk
Sergeant 3
Sergeant 3
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.

Fri Apr 04, 2008 3:10 am

The only thing you have to be careful of is leaks. If you hear a hissing and smell a bad smell, then run the tank outside (if you arnt already, which you always should be when dealing with propane) and unscrew it. A leak of propane can explode, though the tank wont, it will just shoot out gouts of flame.

edit: WOOT 300th post
Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
Post Reply