Hi all,
Is it good to check for leaks with soapy water? I have not done it
because the welding supply guy actually said that the soap is a
petroleum product (oil) and it is bad to have it on your valve
hardware. Instead, he said, test for leaks by looking at the gauges
while the tanks are on and the needle valves are… I forgot. Leave
it for a few minutes and check again, they should be at the same
place. (Yikes, I am relying on my nose.)
Connie
Gas suppliers used to use a thin ivory soap solution for leak
detecting on cylinders. Later they switched to a thin solution of a
foaming dishwashing detergent ( JOY). This can be easily used from
spray bottle or with a soft brush. Some may use a purchased leak
detecting solution, but this is really the same thing minus the dye
color and the scent. A little Dawn or Joy in water is fine! As thin
as will still blow bubbles is fine. You are in no danger if you are
prudent. In the old days well into the 60’s, and later in a few
places, oxygen was compressed in soap water lubricated compressors.
If the machines were kept clean internally of dried soap residues
there were no problems. Ivory flakes were a soap of choice.!! Later
and today oxygen for distribution and cylinder filling was handled as
a liquid and pumped in non lubricated pumps at very low ( - 300 F)
temperatures.
jesse
Not all soaps contain petroleum products…especially facial soap
and soap for tender skin. Those soaps use olive oil, palm oil,or
coconut oil. If you want to test your gas line, you could use
something like Castile soap (if it has a bit of palm oil added,
it’ll make a better lather or bubbles). I remember when I had a
problem with an old gas range, the technician from the gas company
borrowed a bar of Ivory soap (he insisted on Ivory) to make suds to
test the lines. It worked. He found so many leaks that we had to get
a new stove. I don’t know what’s in Ivory soap, but it sure made
bubbles when it hit a hole in the line, and there were no
repercussions.
Dee
I believe it’s pretty much standard to check with diluted dishwashing
soap, and I have never heard that it is bad for the tank. I suppose
you could use 7th Generation or some similar eco-friendly soap that
is known to be made from corn and coconut. The biggest advantage to
‘bubble testing’ (besides lowering the risk of fire!) is that you can
see exactly where the problem is and know if you didn’t hook
everything up properly or if there is a problem with the tank itself.
I even take soapy water with me to get new tanks and test them closed
because when I started out, I had a couple of acetylene tanks with
faulty stems.
The the guy gave you seems strange and dangerous. Only a
big leak would register that quickly, and would anyone want that much
gas in his/her studio while waiting to check? The only thing worse
than not testing or possibly releasing a bunch of gas into the air
would be the old joke of stupidly testing for natural gas leaks with
a lighter! Years ago a friend of mine actually had to talk someone
from the natural gas co out of doing that in her apartment. Yikes!!!
I understand about not wanting to rely on smell. I’ve lived too many
years with stuffiness from allergies to depend on smell alone! 
Victoria Lansford
Connie Hi.
The gauge inspection method will tell you if there is a leak or not.
But the soapy water method will tell you where the leak is. Check
all connections first as that is were it is most likely going to be
leaking from once you have established there is a leak with your
gauge method.
Cheers
Chris
Dee
I agree, natural gas and Propane have no harmful response to soap,
do not apply the same logic to pure oxygen. We will be hearing about
you, not from you.
Terry
Hi Victoria,
The only thing worse than not testing or possibly releasing a bunch of gas into the air would be the old joke of stupidly testing for natural gas leaks with a lighter! Years ago a friend of mine actually had to talk someone from the natural gas co out of doing that in her apartment. Yikes!!!
Testing for gas leaks with a flame is not an ‘old joke’ - it was the
accepted method here right up to probably the 1970’s. When I started
out in the building industry in the early 60’s, no one had heard of
testing with soapy water and I found dozens if not hundreds of leaks
using a match with no ill effects. Of course, large and obvious gas
leaks were not tested for this way but I can even remember leaks on
street mains being deliberately set on fire by the gas repair crews
if they couldn’t repair them immediately as this removed the danger
from gas seeping into basements etc. and exploding. It was very
spectacular to see a 6 foot high flame roaring up from a dark chasm
in the middle of the road! Of course, in those days, all the gas was
coal gas (Methane) - made by heating coal in retorts, collecting the
resulting vapour and condensing off the heavier coal-tar fractions.
Nowadays, all the gas supplied around here is ‘natural gas’, mainly
from North Sea wells and, whilst still being primarily Methane, it
can contain other flammable substances such as Ethane and Butane and
is supplied at a higher pressure. Before you condemn these old
practices out of hand, you must consider what they actually
represented. From the very first use of gas and right up to the
common use of electric lamps which was probably not universal until
the 1950’s, most buildings were lit by gas. Was there anything
special about gas lights? - No, they were usually of two types,
either an open fan shaped flame or an incandescent mantle but, in
either case, the true nature was the same - a hole in the end of a
pipe through which gas leaked and was lit. There were no regulators,
flashback arrestors or what-have-you, just a pipe in from the street
main with a simple shut-off valve for maintenance and a little tap
near each light to adjust the flame height. A gas cooker or torch, of
course, was exactly the same and remains so today except that the gas
line now incorporates a regulator to reduce the higher gas pressure.
It is this change in pressure which really made the change from flame
testing to soap testing leaks, as the flame produced by a leak
nowadays would be substantially bigger than before and could cause
collateral damage to adjacent materials.
Best wishes,
Ian
Ian W. Wright
Sheffield UK
In reqard to soap for testing leaks, yes regular soap should not be
used. In our welding supply store we used only PURE CASTILE SOAP. I
retired many years ago and I do not know if this brand is still on
the market. It did not contail oil.
We have beaten this horse to death many times…
What it comes down to is me meaning of the word “SOAP”
Originally Soap was just that, a fat that had been completely
reacted with a base to form a soap. Has in the chemical meaning of
the word
In today’s world “SOAP” has become a marketing term and can mean
what is chemically a Soap, or a Detergent, or whatever a marketer
thinks will clean… In addition even a true soap as sold today has
often added oils and perfumes as well as other chemicals (Things like
stabilizers and preservatives) added.
In Addition to the person who made mention of using “soap” with
olive oil in it instead of a “petrochemical oil”, because it is
safer… Well I have bad news for you… Oxygen will combust just as
happily with a Vegetable oil as with petrochemical based oil… keep
both far away from pure oxygen, especially under Pressure.
So to recap. If you are not sure it is a chemically pure soap you
are using to make soapy water, buy some ‘leak detector’ that is
oxygen rated. It’s cheap, and for the amount you will use a year it’s
still cheap.
To test Propane, Natural gas or acetylene, you can use almost
anything that will not corrode your lines.
Kay
PS [rant mode on] Yes I HATE with a passion marketers who take
perfectly clear and concise words and twist their meaning to make a
buck [/rant mode off]
Welding shops actually sell a testing liquid which probably is Pure
Castile Soap in water.
Connie,
Jesse Brennan has a lifetimes experience in the compressed gas
industry to back up his suggestions about Ivory soap and Joy
detergent. My much more limited experience agrees with his
suggestions. The only concern I have is that the manufacturers of
consumer products frequently change their formulations to make their
products “New and Improved” and don’t take their use as gas leak
detection products into account. They may change their formulation
in such a way as to make it less than safe for this use in regards to
oxygen systems. The safest method is to use purpose designed leak
detection fluids. This way the determination of a materials
suitability and safety for this use is not your responsibility but
that of the manufacturer.
Jim
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
I find the water and soap test work the best. As well smith torch as
a product out so you can test the connections. All supply houses
carry it.
Andy “The Tool Guy” Kroungold
In addition to the other safety tips on using stored gases: Two
things I haven’t heard
I have seen a regulator where the adj screw blew out and through a
man’s chest, killing him. This was due to oil contamination. This
was at a safety talk given by a Linde rep.
Dan Wellman
Testing for gas leaks with a flame is not an ‘old joke’ - it was the
accepted method here right up to probably the 1970’s. When I started
out in the building industry in the early 60’s, no one had heard of
testing with soapy water and I found dozens if not hundreds of leaks
using a match with no ill effects. Of course, large and obvious gas
leaks were not tested for this way…
Testing for gas leaks with a flame may have been standard practice
at one time but the danger is still too high to think that is an
acceptable practice.
In 1975, I sat on a jury trial in which a house had blown up because
of a gas leak. (This matter took place in the 1960’s or ealy 1970’s,
and took forever to come to trial because the insurance companies
believed if they delayed long enough, the plaintiff, witnesses would
disappear or die or just plain give up.) As a Trial Clerk in the
state of Washington, I was responsible for taking brief minutes for
appelate purposes, for tracking and handling exhibits, and was also
responsible for the jury, among other duties. I had plenty of
opportunity to view the pictures of the destruction of that house,
and of the three other houses that had been destroyed by similar
explosions within a short time of each other. People died in several
of those explosions. I believe the women involved in this trial had
returned home and was entering her home at the time of the explosion.
She didn’t remember anything after the explosion. Her hospital stay
was lenthy. I think she was lucky to have survived. The two story
house was kindling.
This explosions was a leak in her furnace system rather than a leak
in a fuel tank, but the destruction would be similar according to
local firemen who quake at the thought of a fuel tank in a burning
building. There is a reason that finding fuel leaks with a flame
became an unaccepted way to find leaks! How many more homes were
destroyed that did not make national headlines? These four homes
were on the Olympic Peninsula in Washington state.
I wish that I could relay the visual images that I have of the
destruction and victims. Those images will be with me forever and I
hope this message will remain with all users of fuel tanks. I am very
careful with my tanks! Our local welding supply store has a tank that
had exploded on display that makes a very good visual image to remind
us to be very careful. The tank is very thick metal, was blown open,
twisted and deformed as if is were foil manipulated in a child’s
fingers.
We need to be soberly serious when operating deadly weapons such as
fuel tanks. Good health to all! Kitti deLong, a lurker who usually is
weeks behind in reading email.