can any one tell me what the benefit is to changeing from blue bottied gas to propane.what is the difference thanks
gas change
- Thread starter andrew_5104237
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The difference is that propane freezes at a lower temperature than butane ( both types of gas are in liquid form - LPG ) so if you plan to caravan in the winter use propane because if the temperature drops around freezing on butane you will have no gas therefore no heating etc.
Andrew,
Aside from the difference in boiling point between butane (blue bottle) and propane (red bottle), there are other differences:
Propane has only about 88% of the heat content of Butane - you may (just possibly) notice a difference in the time taken to boil a kettle or bake a cake, but you will use about 12% more propane gas to do the same job as with butane.
Propane has a lower boiling point -40
Aside from the difference in boiling point between butane (blue bottle) and propane (red bottle), there are other differences:
Propane has only about 88% of the heat content of Butane - you may (just possibly) notice a difference in the time taken to boil a kettle or bake a cake, but you will use about 12% more propane gas to do the same job as with butane.
Propane has a lower boiling point -40
Rob Jax,correct me if I am wrong but I dont think you mean 'boiling point'I think you mean freezing point,boiling either gas could be a bit of a problem!as LB would say hehheh!
The P, Rob is spot on. The it has turn from liquid into gas in order for us to use it - hence the boiling. If you are out caravanning and your Propane freezes you will be well past brass monkeys time.
Mike A
Mike A
Hi Gary,
There are several "Heat of Combustion" values for the combustible gases in the standards books - the two most commonly used are "Neat Heat ..." and "Gross Heat ...".
As you say one gives a difference of 30%, the other approx 12%.
And I think the 12% difference is the one you experience boiling a kettle, but now I need to check.
Robert
There are several "Heat of Combustion" values for the combustible gases in the standards books - the two most commonly used are "Neat Heat ..." and "Gross Heat ...".
As you say one gives a difference of 30%, the other approx 12%.
And I think the 12% difference is the one you experience boiling a kettle, but now I need to check.
Robert
Is it boiling point, freezing point or a gassing point? Does the liquid need to boil to produce the gas?
I would wager what we're talking about is the gassing point.
(Jumps up into the air hollering, "Strike One", another technical question dismissed with ease!!!)
Lol
Well confused you will be!I still dont think the gas actual boils so perhaps Lol is right as the gassing point,either way when the temperature gets to the levels quoted it stops working usually just after you put the kettle on!
Hi Plotter,
Sorry - the gas is caused by the liquid propane or butane boiling.
Our blue and red gas bottles are just like a pressure cooker.
At home, you put some water in the pressure cooker and heat it up - the water boils and because the lid is sealed, the gas (steam) pressurises the container. Think Ice - Water - Steam
Eventually the pressure stops increasing - it's balanced by the available heat.
If you let some steam escape, more water boils to replace the lost steam (gas) and then equilibrates at the same pressure again.
If you turn off the heat and also let steam escape, then the pressure in the container will drop. Eventually once the temperature inside the container drops below 100
Sorry - the gas is caused by the liquid propane or butane boiling.
Our blue and red gas bottles are just like a pressure cooker.
At home, you put some water in the pressure cooker and heat it up - the water boils and because the lid is sealed, the gas (steam) pressurises the container. Think Ice - Water - Steam
Eventually the pressure stops increasing - it's balanced by the available heat.
If you let some steam escape, more water boils to replace the lost steam (gas) and then equilibrates at the same pressure again.
If you turn off the heat and also let steam escape, then the pressure in the container will drop. Eventually once the temperature inside the container drops below 100
I full support Rob-Jax's description of the process by which LPG (Liquefied Petroleum Gas) stored under pressure is converted to its vapour stage effectively by 'boiling'.
And just like a pressure cooker, it needs a supply of external heat to keep the process working. If you turn off the heat under a pressure cooker, the rate of steam generation and the pressure reduces and eventually as the temperature falls below 100C (Boiling point of water which is inside the vessel), the pressure cooker stops working.
If an LPG bottle is chilled below the boiling point of the LPG (-40C for Propane, and -0.5C for Butane) then just as in the pressure cooker the LPG stops vaporising.
The energy needed to vaporise the LPG is drawn from the heat in the air surrounding the bottle, and in doing so the bottles actually self-cool. That is why Roofers Red Propane bottles can often be seen with a coating of frost when they are using their high powered burners to melt the bitumen.
It is one of also the reasons why gas bottle lockers on caravans have lots of ventilation, rather than lots of of insulation. In fact you will make the problem worse if a gas bottle is insulated as it cannot grab the heat it needs from the atmosphere.
MORAL: Do not insulate you LPG bottles
And just like a pressure cooker, it needs a supply of external heat to keep the process working. If you turn off the heat under a pressure cooker, the rate of steam generation and the pressure reduces and eventually as the temperature falls below 100C (Boiling point of water which is inside the vessel), the pressure cooker stops working.
If an LPG bottle is chilled below the boiling point of the LPG (-40C for Propane, and -0.5C for Butane) then just as in the pressure cooker the LPG stops vaporising.
The energy needed to vaporise the LPG is drawn from the heat in the air surrounding the bottle, and in doing so the bottles actually self-cool. That is why Roofers Red Propane bottles can often be seen with a coating of frost when they are using their high powered burners to melt the bitumen.
It is one of also the reasons why gas bottle lockers on caravans have lots of ventilation, rather than lots of of insulation. In fact you will make the problem worse if a gas bottle is insulated as it cannot grab the heat it needs from the atmosphere.
MORAL: Do not insulate you LPG bottles
Boiling is correct but as said confuses, while freezing to the layman is more understandable and at the end of the day understanding the concept is more important than process.
I could have the same sort of problem describing Carver water heater 'fusible plugs', I say it's filled with wax and this melts if things get to hot, simple. The truth is it's metal not wax but not everybody understands metals can melt at such low temperatures, no one doubts wax can so the essential message gets home.
I could have the same sort of problem describing Carver water heater 'fusible plugs', I say it's filled with wax and this melts if things get to hot, simple. The truth is it's metal not wax but not everybody understands metals can melt at such low temperatures, no one doubts wax can so the essential message gets home.
Oh indeed, this is a confusing subject, but let me try to throw some light on it. The boiling temperature of say for example Butane, is indeed 0 degree centigrade. This however is at atmospheric pressure, which the inside of a gas bottle is not. The boiling point does however indicate the willingness of a gas to turn from liquid to vapour and as such is used commonly.
The difference in cooking time, between butane and propane, depends on the age of the caravan and type of regulator fitted.
For caravans up to 2001, with no in-built regulator, the higher pressure 37mbar of propane more than compensates for the lower calorific value compared to butane on 28mbar.
For 2002-on caravans, with a fixed 30mbar regulator for both types of gas, the lower calorific value of propane is noticeable giving slower cooking, but not in the oven which is thermostatically controlled.
For caravans up to 2001, with no in-built regulator, the higher pressure 37mbar of propane more than compensates for the lower calorific value compared to butane on 28mbar.
For 2002-on caravans, with a fixed 30mbar regulator for both types of gas, the lower calorific value of propane is noticeable giving slower cooking, but not in the oven which is thermostatically controlled.
hello Gary
Try mercury which is well known as a liquid metal, and of course the fusible plug in a C2 is a soft metal compound designed to have a specific melting point known as Wood's Metal, but i appreciate that it does seem unusual and unless you are an engineer such knowledge is uncommon.
Try mercury!, not on your life John, I don't want to put the fear of God into my customers!!
It does illustrate the point though, reminds me of another life which involved cleaning carpets?
"don't call them 'chemicals' or you will frighten the customers... their 'products'"
2004 actually Rodge but probable the main difference is total heat output of the room heater in winter.
Hopefully with 'global warming' this will be less of a problem in the future!!
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