In response to a Question from Fishbre386, I think that
Acetylene is lighter than air, at least I have never heard the
cautions about it pooling like LP.
Two other issues aRe:
It comes in a cyclinder that has a “honeycomb” inside and is
stored dissolved in Acetone. For this reason Acetylene
cyclinders should always be stored, used, and shipped upright.
If it spits liquid during use it is the Acetone coming out.
As a gas Acetylene is unstable above 15psi (explosive) That
is why Regulators redline at 15psi. And also the reason it is
stored in tanks dissolved in Acetone.
I encourage anyone with safety questions to get the safety
brochures most welding suppliers should have. But also be aware
that very many poeple who deal with and use welding gases are
woefully ignorant of safety concerns!!!
Knowledge and the wisdom to apply it properly are one of the
best insurance policies.