Butane not burning mystery.

[Lon nan Gruagach]

Not really because the third element (ignition) for burning/explosion is not present in a sealed cylinder.

There is the auto-ignition temperature, for which no external ignition source is required.
For butane at 1 atmosphere and 40% by volume is about 405⁰C
Gas/oxygen ratio and pressure change this, I cant find any handy graphs for butane, but a much demonstrated example is that of flour in air.

 

[jdc]

That condition ceases when you attach a rubber/ thin-walled copper tube and put a match to the open end!

That's true as far as it goes, but there are limits on the ratios of air to flammable gases outside of which it's either too lean or too rich to light. The too rich limit with Butane is 8.4% by volume of Butane in air. That is to say, if there's as much as 8.4% butane in the mixed gas in said pipe, it won't burn. Unless very cold, it would be hard to have as little butane in the mix as this, so I guess it's quite safe even if perplexing and irritating!

 

[jbweston]

Best way to cure this is to roll a newspaper up and set light to it. Hold the burning paper in front of the bottle valve (with the regulator disconnected) and open the valve. When you get a strong, powerful flame, about 1 metre long you know the air has gone. If you do this on the boat it's obviously best to make sure the valve is pointing overboard, taking care not to ignite any adjacent boats.

Much more exciting entertainment than listening to requests for radio checks on the VHF or playing Scrabble.

 

[Momac]

If the gas doesn't light or doesn't burn properly take the cylinder and give it a good shake around to stir up the liquid gas. This worked for me.