Gas Leak Testing

I was reading with interest the info about safety and oxygen/propane
use. 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.

Thank You. Pat

I was reading with interest the info about safety and
oxygen/propane use. 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? 

It’s not all leak detection fluids. You have to read the
specs/labels. Some are compressed oxygen safe and some aren’t. The
one that Rio ships with it’s torch kits is oxy safe, for example.
This is a case of a poorly worded blanket pronouncement.

Ron Charlotte – Gainesville, FL
@Ron_Charlotte1 OR afn03234@afn.org

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: propanecarbs.com

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

I didn’t catch whatever post said that soapy water is unsafe - but I
guess the entire welding industry is unsafe, then. That’s petty much
what everybody does, and welding books will recommend it, too. All
you need to do, if you’re nervous about it, is rinse it off - no big
deal. Any leak it wouldn’t catch will be so insignificant as to be
meaningless. Quality is necessary, perfection is not.

There are leak detector fluids sold in both welding supply and
hardware stores that are safe for use with oxygen systems. It will
state so on the bottle.

Jim

James Binnion
@James_Binnion
James Binnion Metal Arts

360-756-6550

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."

Leak detector is not the same has soapy water. If you go to Highside
Chemicals web page and then check the GAS LEAK DETECTOR
http://www.highsidechem.com/pdfs/gasleak.pdf

You will see that it is not just soap and water. It has agents added
to be fluorescent and also to modify it’s viscosity as well as it’s
low temperature behavior. Therefore their warning in reference oxygen
equipment may be justifiable. However to leap from taking a chemical
product and extending it to "all leak detecting solutions are
dangerous around oxygen would be like taking the warning about nitric
acid and saying it is dangerous to use Vinegar on my French fries,
because both are acids.

Kay

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. 

Second reply to my post: I just learned from this thread that there
are oxygen safe leak detector solutions. The bottle I have is unsafe,
I never bothered to look for another kind. We’re never too old to
learn something new…that’s what I love about Orchid.

Hopefully, this has been helpful in the other direction too. Some
leak detectors are not safe for use with oxygen.

Howard Woods
Eagle Idaho.

Many thanks to the four of you who replied with helpful info on the
question I had about checking for propane/oxygen tank leaks…this is
the first time I have used the Ganoksin site and I am impressed by
the helpfulness and willingness of its readers to share…

thanx again…Pat

I dont solder much, and use the small propane tanks you get at the
hardware store, and a Little Torch. When I so solder, I so it in my
garage (a little ventilation, but not much). I have a water heater
in the garage. Should i be nervous? Do I need a propane dettector?

Todd

I use nearly the same setup, I solder in the basement where my
furnace (propane), water heater (propane) and a gas dryer (propane)
are. I have gone through 3 of the camping bottles of propane so far,
and I have had no problems or odd smells to worry over.

I think your garage would have better ventilation than my basement
even though it is a walkout. I am in the basement a great deal and
see no need for a propane detector, and I really wouldn’t see one in
your situation as being helpful either unless you smell something?

Terry

I found some stuff at Four Corners Welding & Gas Supply, Gallup.

It’s sure-chek All-Temperature Fluorescent Gas Leak Detector. Safe
for oxygen use - Non-corrosive to metals - safe for polyethylene
pipe. Non-toxic, safe to use with air, refrigerants, nat. gas and
propane. Meets MIL-L-25567D, SEC. 4.4.9 For Use on Oxygen Systems.
Product of LA-CO Industries, Inc. - 1201 Pratt Blvd., Elk Grove
Village, IL 60007-5746, U.S.

16 fl. Oz. spray bottle cost me US$8.41 - Store mgr. said I could
dilute it halfway with water and get 32 fl.oz.

Dan Woodard, IJS

I have seen the aftermath of a propane leak. As propane (LP) is
heavier than air it will collect and pool in a low spot until it is
concentrated enough to be explosive. The incident I saw was where
there was a leak in the line between the tank outside and the
modular home. The leak traveled 25 feet or more under ground and
followed the line up under the house. When the homeowner attempted to
light his furnace it blew the door off of the closet and burned him.
The line was supposed to come out above ground and re-enter at
another point before going to the regulator, it didn’t; Boom. Usually
the regulators are located outside for this reason. Please use a
detector for any area where it might be possible for the gas to
collect and pool.

Dan Wellman