Propane / Acetelyene

Propane / Acetylene (Was:Torch - drawback)

The topic of which gas is more dangerous comes up regularly on
Orchid.

Both propane and acetylene have their own individual pluses and
minuses when it comes to safety.

Many people seem to focus on the fact that propane is heavier than
air and tends to pool. This is absolutely true, but… when a
combustible gas leaks in an enclosed space such as a home studio
with limited ventilation, it doesn’t make much difference whether
the gas is heavier or lighter than air. If it has no place to go it
will accumulate until it can somehow dissipate via an open window or
through ventilation. If it sees a spark before it dissipates then
it has a real good chance of exploding.

My approach to safety with these gasses is to minimize the amount
that I keep in my home studio. I use propane and MAPP gas and limit
the amount in my home to one disposable tank of each. Smaller
inventory of gas means a smaller explosion , if the gas does indeed
ignite.

If acetylene was available in small disposable containers ( and I
believe that it is not) I would probably still not use it. This is
because acetylene has a much greater explosive range than propane.
I don’t have the numbers handy, but acetylene can explode over a
very large range of concentrations in air, while propane has a much
smaller explosive range. This means that gas from a tank of
acetylene leaking in an enclosed space (your studio) has a greater
chance of exploding than the gas from tank of propane leaking at the
same rate…

The other thing I do is make sure that all of my connections are
tight and that I close the main valves when I am done for the day.

Jewellery is a hobby of mine, my day job is working as a chemical
engineer for a large oil company. I have 25 yrs of experience with
combustible gases and with designing large gas plants to process and
handle these gases safely.

Milt Fischbein
Calgary Canada

    Both propane and acetylene have their own individual pluses
and minuses when it comes to safety. Many people seem to focus on
the fact that propane is heavier than air and tends to pool.  This
is absolutely true, but.... when a combustible gas leaks in an
enclosed space such as a home studio with limited ventilation,  it
doesn't make much difference whether the gas is heavier or lighter
than air.  If it has no place to go it will accumulate until it can
somehow dissipate via an open window or through ventilation.  If it
sees a spark before it dissipates then it has a real good chance of
exploding. 

Which is only one of the reasons that good ventilation is important
in about any kind of a workshop, Milt.

Margaret