Changing from Butane to Propane

[Stephen_374341239]

Hi There

I wish to change from butane to propane on my caravan 2007 model.

I have the new reg on the bulk head so this does not need changing. I have a new hose connector for the propane cylinder.

What I wish to know can you mix the gases or do I need to vent/purge before connecting the new propane cylinder?

Reards steve.

 

[ProfJohnL]

Hello Stephen,

If I understand you correctly, you have a single bottle system and you to change form butane to propane. As the regulator is common to both gasses, then all that is required is to change the pigtail (Connector between bottle and regulator).

If you have a twin bottle system and intend to have one butane and the other a propane bottle, they must be connected in such a way that it is impossible for the bottles to cross feed in any way to each other.

If you have twin bottle system with out the above protection you need to change both bottles and pigtails.

As the pigtails operate at bottle pressure It would wise to have them changed by a competent fitter who will have all the necessary equipment to test the system after the change.

 

[Stephen_374341239]

Hi John L

Just a single bottle system. No problem changing the pigtail after all your changing one end every time you change a new bottle of gas. I would not dream of making any changes to the system passed the reguator as I am not qualified. I think you have anwsered my question you say some people run butane and propane so mixing of the gas in the pipes on change over connot be a problem this is all I needed to know.

 

[rob_jax]

Hi Steve,

Just to confirm what you and John have stated - there's no issue burning Propane or Butane or any mixture of the two gases in modern caravan gas appliances.

Indeed what you bought in the bottles as "pure" Propane or Butane contains small amounts (1% or so) of the other gas as a manufacturing impurity anyway.

And I agree with John - do a leak test on both pig-tail joints afterwards - depending on temperature, Butane has a bottle pressure of around 2 to 4 bar (30 to 60 psig), but Propane has a bottle pressure of around 8 to 16 bar (100 to 200+ psig) - and is more likely to seek out a leaky joint.

Robert

 

[Stephen_374341239]

Hi Robert

The only reason for the change is Calor are bring out the new light weight propane cylnder in March which at 4.52kg is virtually half the weight of old steel model. Two full old steel cylinder type come in at 30kg. Two new Calor light at 9.04kg weight saving of 20.96kg that i am not pulling around.

ps Do not tow with 4x4 so every little helps.

 

[Robtel]

Quote from Stephen:

"Hi Robert

The only reason for the change is Calor are bring out the new light weight propane cylnder in March which at 4.52kg is virtually half the weight of old steel model. Two full old steel cylinder type come in at 30kg. Two new Calor light at 9.04kg weight saving of 20.96kg that i am not pulling around.

ps Do not tow with 4x4 so every little helps. "

I've had a look at the calorlight for exactly the same reasons as you've stated but could I ask you to check your arithmetic. My understanding is that the empty containers weigh in at 4.52kg but you still need to add the 6kg of gas to that before comparing it against your "full old steel" cylinders. It still works out lighter in weight but perhaps not as much as you think.

 

[rob_jax]

Hi Steve,

Sounds like a good idea - you'll save 50% of the bottle casing weights - and as you say that comes straight off the nose-weight.

The point about the leak test is that if you check it now in the winter, by the time summer comes around the bottle pressure on a warm day will be around 150 to 200 psig - and so it's a good idea to leak check the connections again...

Robert

 

[Stephen_374341239]

Quote from Stephen:

"Hi Robert

The only reason for the change is Calor are bring out the new light weight propane cylnder in March which at 4.52kg is virtually half the weight of old steel model. Two full old steel cylinder type come in at 30kg. Two new Calor light at 9.04kg weight saving of 20.96kg that i am not pulling around.

ps Do not tow with 4x4 so every little helps. "

I've had a look at the calorlight for exactly the same reasons as you've stated but could I ask you to check your arithmetic. My understanding is that the empty containers weigh in at 4.52kg but you still need to add the 6kg of gas to that before comparing it against your "full old steel" cylinders. It still works out lighter in weight but perhaps not as much as you think.

Hi

I was getting my info from The caravan club magazine December 2007 page 9.You can only go on what you read. You could be right but it still lighter. Many thanks for pointing that out. Do you think calor gas will bring in lighter butane bottles.