acetylene regulator question

I recently up-sized my acetylene cylinder from a 40cf (B) to a 60cf
(wq)tank.
When I tried to attach the spud end of the regulator to the new
cylinder, the regulator gauge hits the rim of the cylinder so i
couldn't tighten the regulator spud nut. I stopped by the hardware
store (the welding store was closed by now) and (of course) they didn't
have any regulator parts. But they did have brass fittings. I removed
the spud from the regulator and replaced it with a 1.5" double ended
brass fitting, then a brass coupler, then the original spud (to
lengthen the spud). I used teflon tape on all the fittings. It works
fine with no leaks. The regulator is brass so i figured brass fittings
are adequate.(i know copper is not)
Does anyone have any thoughts or safety concerns with this set up?
thanks,
walt
Reply to
wallster
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I would buy the correct nipple for the regulator ASAP. My friend cobbled something like this up for a Nitrogen tank and regulator once, it exploded when he opened the valve. The surgeons stitched his hand back together, but he will never have full use of it. I know that Acetylene pressure is less than 300PSI compared to the Nitrogen at 2500PSI or higher, but pressurized gas is not something to mess with.
Reply to
Ron DeBlock
thanks Ron, good advice. I guess if i have to ask, i already know the answer. I'll get a the longer spud. Acetylene released at 300psi could be catastrophic.
walt
Reply to
wallster
that's odd. Victor lists their regulator as "All brass acetylene regulator (CGA200)" and brass is 70% copper and 30% zinc. The fittings I used were brass, same as the regulator. What material do they recommend as acceptable?
walt
Reply to
wallster
BOC (British Oxygen) specify that joints or fittings in contact with acetylene must not be of copper or any alloy containing more than 70% copper.
Jim
Reply to
pentagrid
hey Ron, picked up the new longer spud from the welding supply store. $3.90... now i dont have to be concerned. thanks again.
walt
Reply to
wallster
I can't say with unequivocal certainty, but most heavily machined fittings are free-machining yellow brass, 37% Zn, 3% Pb, ~59% Cu, which would fit with the requirement below.
Tim
-- "California is the breakfast state: fruits, nuts and flakes." Website:
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Reply to
Tim Williams
"Unspecified brass is probably OK - but are you feeling lucky?
Jim"
Not really, that's why i bought a longer spud. The new spud appears to be brass as well, I just thought it odd that copper can make acetylene volatile yet brass is (approx) 70% copper. I dont doubt your statement and I realize "brass" is a bit generic, but it still seems odd. The biggest difference between my "cobbled" extension and the correct regulator spud is the wall thickness (and the fact that it's one piece and not three peices). I realize the cylinder pressure is about 300psi but I will sleep better knowing that the proper application has been applied. Thanks for the insight Jim. walt
Reply to
wallster
That's good! We don't want to hear about you on the news (unless it's something good, of course!)
Reply to
Ron DeBlock
Verbatim quote with no further info. However "brass" is a pretty elastic term.
From "Casting Brass" CW Ammen :-
Yellow Brasses 63 to 72% Cu Red brasses 83 to 85% Cu Aluminium bronze 81 to 89% Cu
Unspecified brass is probably OK - but are you feeling lucky?
Jim
Reply to
pentagrid
FYI.
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" a.. Acetylene forms explosive compounds with copper, brass, copper salts, mercury/mercury salts, silver/silver salts and nitric acid. Under no circumstances should acetylene gas come in contact with unalloyed copper, except in a torch. Any contact of acetylene with high-alloyed copper piping will generate copper acetylide, which is very reactive and may result in a violent explosion. Also, an explosion hazard will result if the gas comes into contact with silver bearing materials such as those used in silver-brazed pipeline joints. "
Ken.
Reply to
Ken Davey
Hey Ken, I cant believe more people dont get blown up based on all the warnings that acetylene comes with. I very (maybe twice) seldom have ever heard about acetylene exploding. There are tons of automotive service establishments that use it everyday along with steel fabricating companies, ship yards, etc... But apparently it's a BAD idea to fill rubber balloons with acetylene and store them behind your truck seat. Good old static electricity can be a problem.
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walt
Reply to
wallster
Wow. I knew acetylene was dangerous, but I didn't realize it was THAT dangerous. It's amazing that miners used to (and some spelunkers still) wear acetylene generators on their foreheads!
Btw, I'm curious about these two safety statements:
"If this reaction or ignition occurs within the torch base or supply hose it can propagate back into the storage cylinder causing it to explode violently."
"Flame arrestors and check valves should be installed at both the torch base hose connections and at the regulator hose connections."
In light of the former statement, wouldn't you also want a flame arrestor installed at, or within, the cylinder valve?
- Michael
Reply to
DeepDiver

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