Propane == Butane ?

[DrZhivago]

Dumb question. Googled loads of stuff about relative advantages of propane vs butane, but nothing about whether they are interchangeable. Goes without saying?

In other words, if I change from propane to butane or back again, would I need to re-jet the burners and/or change the pressure regulator? I have some bottles of both types lying around and would like to use them.

 

[DaveA1]

You well only need to change the regulators, they are coloured the same as the gas bottles.

 

[MichaelE]

If you have a bulkhead regulator in your van then all you have to do is change the tails to this to suit the type of bottle you use.
If no bulkhead then a change of regulator will do the trick.
Regards re jetting the jets, there is a difference between propane and butane, but from what i understand as im not a gas engineer devices in vans are fitted with jets to run on butane. To get the best out of using Propane(it burns hotter) you would have to re jet to propane ones, but your are unlikely to notice any difference and they will work perfectly if you don't change them.

 

[Damian]

As has been said, if you have a bulkhead mounted regulator then you only need to change the pigtail to suit the gas you want to use.
As for rejetting, you do not need to even think about that, all caravan gas equipment is jetted to take 28mb or 37mb, and the 30mb as supplied by the bulkhead regulator.

 

[DaveA1]

As has been said, if you have a bulkhead mounted regulator then you only need to change the pigtail to suit the gas you want to use.
As for rejetting, you do not need to even think about that, all caravan gas equipment is jetted to take 28mb or 37mb, and the 30mb as supplied by the bulkhead regulator.

This is stated on each of the appliance specification labels.

Thought Butane burnt hotter? Sorry if i'm wrong.

 

[ProfJohnL]

You well only need to change the regulators, they are coloured the same as the gas bottles.

No!
there is no regulation or code of practice that defines the colour of Propane or Butane bottles or regulators Calor uses Red for Propane and Blue for Butane, but other suppliers can and do use different colours.

As for which gas "burns hotter" A propane flame at its hottest point in air is about 1930C compared to butane at 1900C, that is a 30C difference of about 1.5%

However from a users perspective that temperature difference is not even noticeablke as its other characteristics of burning LPG that will swamp that difference.

Effectively what you need to know is how long will it take to boil that kettle, and how much gas will be used.

There are a whole raft of factors that affect this result, but effectively for a delivery pressure of 30mB (the current EU standard for both Propane and Butane) Butane will deliver approximately 20% more heat energy per unit time into the kettle than Propane. So if all other factors are equal, a kettle on butane will heat up faster than on Propane.

But gas heating power is not the only detail factors involved, so in practice the effective differences are actually quite small and probably only about 10%. Where the appliance has a genuine variable gas throughput thermostatic control, such as Gas space heater, Oven and fridge, the thermostat will adjust the gas input rate relative to the required temperature and reduce the differences even more.

Purely based on the net calorific value of the gas per kg where propane is 46(MJ/kg) and butane is 45.6(MJ/kg), and as similar sized butane bottles tend to have a greater weight of gas than Propane, Butane bottles will last about 15% longer.

If you are caravanning in temperatures below about 4C you should be using Propane, If all you caravanning is above 4C then Butane will be fine.

 

[MichaelE]

As has been said, if you have a bulkhead mounted regulator then you only need to change the pigtail to suit the gas you want to use.
As for rejetting, you do not need to even think about that, all caravan gas equipment is jetted to take 28mb or 37mb, and the 30mb as supplied by the bulkhead regulator.

This is stated on each of the appliance specification labels.

Thought Butane burnt hotter? Sorry if i'm wrong.

You are in fact correct , In ideal conditions Butane does burn hotter than propane.The propane regulator is higher pressure to compensate.
To add further confusion a butane gas cylinder will produce lower pressure once the bottle temperature drops below 10 C The bottles actually get colder in use so again will reduce pressure and will affect its efficiency.

 

[ProfJohnL]

... In ideal conditions Butane does burn hotter than propane.The propane regulator is higher pressure to compensate.
To add further confusion a butane gas cylinder will produce lower pressure once the bottle temperature drops below 10 C The bottles actually get colder in use so again will reduce pressure and will affect its efficiency.

Micheal please see my slightly earlier reply. Flame temperature in air 1930C Propane 1900C Butane!

http://www.awsgroup.co.za/data/L.P.G.pdf
Butane is not hotter, but it heats more quickly because a greater volume of calories is released in the burner.

As a comparison of principle, One candle will have a flame with a given temperature, By lighting a second candle the temperatures does not go up but the heating capacity has doubled. Butane is a more dense gas so it carries more heating capacity.

In terms of appliance efficiency, provide the gas is supplied at the regulated pressure the efficiency will remain the same.