On 12/19/11 2:53 AM, Dick Floyd wrote:
>
> ps: I have had a couple of IMCO pipe lighters for about 10 years that
> can't go more than a day without sputtering, spitting out jets of flame,
> etc no matter how much I clean them in "approved ways"& other desperate
> attempts at a solution. They started this behavior very soon after I
> bought them. They ain't my everyday lighter...
Me too! I see David Griffith had one that he filled new with Vector
butane, and it sputtered. T-boy said he'd kept one in his jeans for two
years without a problem.
I'm back to blaming pentane. The MSDS for my Ronson butane says it's
isobutane. That should be better than butane because it has a lower
boiling point and higher vapor pressure. I'm suspicious because it's
labeled butane except for one tiny word, and it's unlikely that it's
100% pure anything.
Officially, butane can be 5% other hydrocarbons because it's hard to
remove them completely. One kind of pentane boils at 82F. Another
boils at 97F. The third boils at 49F. By comparison, butane boils at
30F and isobutane at 11F.
When you press the valve, the temperature of the expanding gas is
probably well below 82F and could be below 49F. I think pentane can
condense between the valve and the nozzle, and this can cause
sputtering. Perhaps the design of the IMCO makes it especially vulnerable.
The warmth of my shirt pocket may help pentane droplets to evaporate.
As a liquid, pentane is 4% heavier than butane. I suppose they could
separate in a butane can. Then, when you invert the can to fill the
lighter, you could get disproportionate pentane in the lighter.
Shaking a butane can before refilling might reduce the chance of
sputtering. Warming a lighter before purging might keep pentane from
remaining as a liquid in the lighter.