gas bottle measurement
Submitted: Tuesday, Jun 10, 2008 at 20:42
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Member - shane (SA)
could someone tell me is a 9kg gas bottle 9 lts ? gas bbq bottles seem to measure in weight and auto bottles in ltrs.
cheers shane.
Reply By: Col_and_Jan - Tuesday, Jun 10, 2008 at 21:14
Tuesday, Jun 10, 2008 at 21:14
I have read once that a litre of LPG (compressed as a liquid as in the gas bottles) is approximately 0.5 kg.
So 9 kg would be roughly 18L and at 70cpl = $12.60 if you could fill it with auto LPG which is another story.
Col
AnswerID:
309102
Follow Up By: Col_and_Jan - Tuesday, Jun 10, 2008 at 21:28
Tuesday, Jun 10, 2008 at 21:28
Looked it up a bit better. Propane is about 0.51 kg p L, which would give you about 17.6 lt. Butane is about 0.58 kg p L which would only give about 15.5L. So somewhere between 17.6 and 15.5 Litres depending on the mix. Source is
http://
forum.onlineconversion.com/showthread.php?t=4858
Col
FollowupID:
575132
Reply By: Member - David P (VIC) - Tuesday, Jun 10, 2008 at 21:15
Tuesday, Jun 10, 2008 at 21:15
Specific gravity of butane/propane approx 0.6 therefore 9 devided by .6 around 15L I would think
AnswerID:
309103
Follow Up By: Richard Kovac - Tuesday, Jun 10, 2008 at 21:19
Tuesday, Jun 10, 2008 at 21:19
David
You have to allow for compression
Boyle's law
p1 x V1 = p2 x V2 = p3 x V3
Richard
FollowupID:
575130
Follow Up By: Col_and_Jan - Tuesday, Jun 10, 2008 at 21:41
Tuesday, Jun 10, 2008 at 21:41
Richard,
You could include the Ideal Gas Equation which also takes into account T (temperature), which ideally would be quoted in Kelvin rather than degrees centigrade. We should also consider the effect of thermodynamics, where if the gas in the container were subject to random but sudden changes in direction, there would be an increase in the kinetic energy of the particles. This could be as a result of movement during transportation. The chaos of the randomly moving particles, which we should consider Brownian Motion, would also have a small, but significant effect on the specific gravity of the combined gases.
Col
FollowupID:
575135
Follow Up By: Richard Kovac - Tuesday, Jun 10, 2008 at 21:49
Tuesday, Jun 10, 2008 at 21:49
Col
That would be adding Charlie's law as well. that getting a little out there.. LOL
Richard
FollowupID:
575138
Follow Up By: Col_and_Jan - Tuesday, Jun 10, 2008 at 22:24
Tuesday, Jun 10, 2008 at 22:24
Yep, I'm still trying to work out how to transfer some of the LPG from my car into the 9 kg bottles.
Col
FollowupID:
575150
Reply By: rags - Tuesday, Jun 10, 2008 at 21:27
Reply By: Member - shane (SA) - Tuesday, Jun 10, 2008 at 21:31
Tuesday, Jun 10, 2008 at 21:31
thanks all. cheers shane.
AnswerID:
309107
Reply By: Member - Davoe (Yalgoo) - Tuesday, Jun 10, 2008 at 22:03
Tuesday, Jun 10, 2008 at 22:03
sheesh you guys do it the hard way!
the water litres should be printed on the bottle pretty sure it is something like W5.5
AnswerID:
309124
Follow Up By: Richard Kovac - Tuesday, Jun 10, 2008 at 22:06
Tuesday, Jun 10, 2008 at 22:06
Thanks, Thats my something new for the day
Cheers
Richard
FollowupID:
575147
Follow Up By: Member - Footloose - Tuesday, Jun 10, 2008 at 22:46
Tuesday, Jun 10, 2008 at 22:46
Ditto.
FollowupID:
575152
Follow Up By: Bware (Tweed Valley) - Tuesday, Jun 10, 2008 at 23:30
Tuesday, Jun 10, 2008 at 23:30
You are always a good source of common sense Davoe. Add the advice you have for the 80 series (and others for that matter) and I reckon you are one of this site's best contributors.
regards
Brian
FollowupID:
575162
Reply By: blown4by - Tuesday, Jun 10, 2008 at 23:37
Tuesday, Jun 10, 2008 at 23:37
Don't forget the ullage valve bleed line is set at 80% volume (by law) so you can never fill the bottle above 80%. This is to allow for expansion of the liquid due to a rise in temperature which if filled above 80% would exceed the capacity of the cylinder on a 50 degrees C day which would cause the safety valve to vent to atmosphere the over pressure thus saving a big bang. The cylinder should have its water (liquid) volume stamped on it (by law) and the amount you actually get in it should be 80% of that amount. Years ago they used to weigh them before and after every time they were filled and you paid by weight for the product but the gas companies worked out that they couldn't rip us off if they sold it that way so they changed it. The 45kg cylinders dont even have a gauge on them either.
AnswerID:
309145
Reply By: Member - Bucky (VIC) - Wednesday, Jun 11, 2008 at 06:10
Wednesday, Jun 11, 2008 at 06:10
Shane
I get one of my 9kg bottles topped up, at a local servo, yes there are still some that don't swap'n'go. The bloke there actually tares off the bottle, and fills it to approx 9 kg's. +/- 0.5 kg's.
I'm happy at that.
I pay for the difference.
The other 2 are swap'n'go type ones, and they are always empty.
Replacement ones are 9 kg's.
Cheers
Bucky
AnswerID:
309158
Follow Up By: DIO - Wednesday, Jun 11, 2008 at 09:30
Wednesday, Jun 11, 2008 at 09:30
If gas bottles are being re-filled for customers, weighing is the correct way of doing business. As you are buying by weight (as with any other commodity) it should be weighed. Any other method of calculation should be declined/refused UNLESS they have a measuring gauge/meter on their re-filling appliance (which they don't).
FollowupID:
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