Gas Bottle Exchange best prices - Page 3

“Classic man” you are posting incorrect information to people.

The price of Butane versus Propane per kg is the exact same price. The cylinders sold with Propane are a 11kg cylinder and Butane are a 12.5kg cylinder.

The gas that is expelled from the cylinder of Propane is at a lower pressure- equating to some appliances not working as efficiently with a lower gas pressure on Propane as Butane- so as the price per kg is the same, WHY take the chance?

I still do not agree with you completely.   I have no idea of current prices for bottles as it's a long time since I bought one and they change according to season and decrees by the Government.

The static pressure in a propane tank varies from 100 to 200 psi.according to temperature.  This is the input pressure that your regulator will see.  This is reduced by the reg to 37mbar or 14"wg.  This is what your appliance sees IN THE UK.  The fitting on the reg is a POL fitting (bull nose LH thread) and will NOT fit a butane cylinder.

The output from a butane regulator is 28mbar  or 11""wg.  The connection is a LH thread loose nut type. Again that applies to the UK.

In Spain there is only one type of regulator available and both propane and butane bottles have the same connection and the output pressure to you appliance will be around the value given above for butane.  The ones I have checked tend to vary.

So what I am saying is that whatever gas you buy in Spain, even though the vapour pressures will vary over a big range, what your appliance will see will always be around 28mbar. That is the purpose of the regulator.

If you apply 37mbar to a butane appliance the flame will have a tendency to lift off the burner and blow out. (not recommended) You just have to turn the burner tap down a bit and it will burn OK.

 It is ONLY in the UK where your delivery pressures vary according to gas type.

I have attached a page from one of my old books showing the different vapour pressures for the different gasses at varying temperatures.  As  it's old, like me, its in Imperial. I'll leave you to convert them.

It clearly shows why butane will not come out of the bottle at low temperatures and why propane will.