Pat
If it is unsafe to use leak detectors or soapy water to check for
leaks, then how can you be sure your tanks are not leaking when
you use the torch the first time after reattaching your lines? I
checked mine when I first got them and connected everything and I
had leaks so I reconnected and tightened up everything and then
checked again with leak detector. Need to know alternative way to
test and safely use.
since I was the one that mentioned leak detector, I will take
responsibility for the reply. Leak detector is perfectly safe for
detecting propane leaks. (Using propane indoors is another matter.)
It is possible for it to react with oxygen if it contains soap or
glycerin to promote bubble formation. I especially keep it away from
regulator internal parts…
OK…after shooting off my mouth without documentation, I stepped
into the garage and found my dusty 25 year old bottle of leak
detector. Brand name: Highside Chemicals Inc. The instructions on the
bottle: Caution “Not for use with oxygen equipment.” The label
purports the use to be for refrigeration, heating, and pneumatic
equipment and “most other gas carrying pipes and equipment.”
My method for leak detection is to use my regulator gauges after
installing a fresh tank of gas. High pressure oxygen will always have
at least two gauges…one that measures pressure upstream of the
regulator and one that measures pressure downstream of the regulator.
I turn on the gas, bring everything up to proper pressure then turn
off the tank valve and shut the regulator supply to the hose. I write
down the exact pressure reading then check over a period of 20
minutes for any drop in pressure on either side of the regulator. A
significant leak will show a pressure drop right away. A slower leak
will show a pressure drop by the end of the 20 minute wait. A change
on the high pressure side means that you need to tighten the
connection to the tank. On the low pressure side, you could have a
hose connection leaking, a leaky hose, or a leaky handle valve.
Again…get documentation from your welding supply store and ask
them about leak detection.
A note about propane and other fuel gases: Propane is a molecule
composed of three carbon atoms and eight hydrogen atoms having a
molecular weight of a hair over 44 Daltons.
Acetylene molecules are two carbon atoms with two hydrogen atoms
having a molecular weight of 26 Daltons.
Air is 80% nitrogen with molecules composed of two nitrogen atoms
each with a molecular weight of 28 Daltons. About 20% of air is
oxygen with molecular weight of 32 Daltons. This gives air an average
molecular weight of 28.8 Daltons.
Gas density is directly proportional to molecular weight. Propane is
much denser than air and tends to collect at the low points in the
house…basements and under the floor. For this reason, it is against
fire code to have propane tanks indoors. I would absolutely never use
it in a basement (I have been known to have a 5 gallon propane tank
in the garage before.) Building code for garages requires all
electrical outlets to be placed higher off of the floor due to danger
of heavy gasoline fumes collecting near the floor. This still does
not make propane legal to store in the garage…it just makes it
somewhat safer than storing in the house.
Acetylene is only slightly less dense than air. (Often said to be
“lighter” than air), It is close enough that it will mix fairly well
with air, but if anything collect near the ceiling.
When choosing a fuel gas, there are three important safety
considerations: Density…where will it collect and how does it mix;
Ignition temperature…how easily does it ignite; and mixture
concentration explosive limits…what is the concentration range in
air over which it will ignite.
Hydrogen and Acetylene have far greater ranges of concentration
through which they will ignite check out
Propane ignites easily like Acetylene. While the range of explosive
concentrations is much lower, the high comparative density means
that it will concentrate more easily than Acetylene. You only need to
reach the minimum explosive concentration for the ignition to occur
in the presence of sufficient heat. For propane properties, check out
this site: http://www.propanecarbs.com/propane.html
Acetylene will ignite at a lower temperature even than hydrogen
check out this site:
http://energyconcepts.tripod.com/energyconcepts/combustionfluegasses.htm
I, personally have taken to using a water torch. I think it is the
safest solution to using a torch indoors.
Acetylene will ignite at a lower temperature even than hydrogen
check out this site:
http://energyconcepts.tripod.com/energyconcepts/combustionfluegasses.htm
I, personally have taken to using a water torch. I think it is the
safest solution to using a torch indoors.
Howard Woods
Eagle Idaho