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Gallery, Projects and General => How do I?? => Topic started by: mhh on January 14, 2014, 11:34:13 AM

Title: Pressure inside a small LPG gas cannister?
Post by: mhh on January 14, 2014, 11:34:13 AM
Hi!
I'm sitting here with a small 0.5kg gas cannister and wondering about how much pressure there is in at 21°?

Is there anyone in here that knows anything about this?

Another question is... How much pressure is it save to put in it?

Any help is welcome!
Title: Re: Pressure inside a small LPG gas cannister?
Post by: John Rudd on January 14, 2014, 11:43:04 AM
Couple of bits of info missing here....
What gas is it?

Propane gas a different vapour pressure to butane...

What is the canister made from.....?



The canister has a vour space in it too, so you cannot completely fill it....
Title: Re: Pressure inside a small LPG gas cannister?
Post by: bcassel on January 14, 2014, 11:43:42 AM
Well, propane converts from liquid state to gaseous at 8.17 bar, or 118 psi.  So, if there is any liquid in the tank, it must be at 118 psi in the tank to keep it in a liquid state.
Title: Re: Pressure inside a small LPG gas cannister?
Post by: mhh on January 14, 2014, 11:49:09 AM
Couple of bits of info missing here....
What gas is it?

Propane gas a different vapour pressure to butane...

What is the canister made from.....?



The canister has a vour space in it too, so you cannot completely fill it....

It is butane/propane mix

I think the canister is made of thin steel..... How does this affect the pressure?
Title: Re: Pressure inside a small LPG gas cannister?
Post by: mhh on January 14, 2014, 11:52:24 AM
Well, propane converts from liquid state to gaseous at 8.17 bar, or 118 psi.  So, if there is any liquid in the tank, it must be at 118 psi in the tank to keep it in a liquid state.

Oh! Well that makes sense! I think that is all the answer I need!
Thank you!
Title: Re: Pressure inside a small LPG gas cannister?
Post by: awemawson on January 14, 2014, 12:59:48 PM
Presumably temperature affects the pressure at which the liquid / gaseous states co-exist? Is that at a nominal 20 deg C or what ?

Andrew
Title: Re: Pressure inside a small LPG gas cannister?
Post by: bcassel on January 15, 2014, 12:27:50 AM
Vapor pressure (at 21 °C or 70 °F) : 8.587 bar
Title: Re: Pressure inside a small LPG gas cannister?
Post by: Arbalist on January 15, 2014, 06:00:29 AM
Well, propane converts from liquid state to gaseous at 8.17 bar, or 118 psi.  So, if there is any liquid in the tank, it must be at 118 psi in the tank to keep it in a liquid state.

Good man!  :thumbup:
Title: Re: Pressure inside a small LPG gas cannister?
Post by: 75Plus on January 15, 2014, 10:55:16 AM
Thiis should give you an idea.

http://www.engineeringtoolbox.com/propane-vapor-pressure-d_1020.html

Joe