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Oxy Acetylene bleeding

Leigh B

Cast Iron
Joined
Oct 30, 2007
Location
South Dakota
I just bought an Oxy/Acetylene torch outfit and I'm wondering what the correct bleeding order is. I thought from my days of tech school (30rs ago) the shut down order is turn off the acetylene first then the ox, but I could be wrong. So what is the correct shut down sequence? thanks for helping
 
I just bought an Oxy/Acetylene torch outfit and I'm wondering what the correct bleeding order is. I thought from my days of tech school (30rs ago) the shut down order is turn off the acetylene first then the ox, but I could be wrong. So what is the correct shut down sequence? thanks for helping

I imagine you will get different responses from different people, but Victor Equipment Co. states in their "Welding, Cutting and Heating guide to "First, shut off the torch oxygen valve, then shut off the torch fuel valve, there are 7 more steps after that "

FWIW that's also the way I learned to do it in a certified Basic welding training class.

It might be worth it to get one of these guides to refresh your memory. They can be had for a few $ used on the web, or ordered direct from Victor. I'm sure AWS also has some literature too. I'm never ceased to be amazed at how unsafe people are with such dangerous equipment sometimes...especially regarding OAW. Don't take someone's word on a chat board...get some procedure from a reputable manufacturer of quality equipment.

:cheers:
 
Which of course begs an interesting question....

When is the last time on a CNC cutting machine you saw someone bleed down the regulators, or torches at the end of the shift?
 
For that matter when was the last time on a cnc machine you saw someone screw out the regulator before turning the gasses on?
 
I assume you mean which one to turn off first when the torch is already lit?

Turning off acetylene first will allow the oxygen to pop off any little bits of heated metal that are clinging to the tip. This is the way I was taught over 30 years ago and my standard practice since. Turning off oxygen first simply leaves a yellow flame which will deposit carbon all over you and your shop.
 
Yeah maybe I should have said:
What isthe best proceedcure to shut a brazing tourch off when lit?
I was taught, turn the acetylene off, then the oxygen, which kills the flame quickly with no carbon build up. This seems to be correct.

Then, What is the best proceedure to blead the lines? Which is a different thing that shutting down the torch.

John, you are right I need to get a guide. I may actually still have my old books from Tech School, I gotta go looking.

thanks to all for helping.
 
Leigh,

Good idea on searching out that literature. In the meantime here's a scan from the Victor guide I mentioned this morning for shuting down a lit O/E torch... you may have to click on the image twice to get to full resolution



fwiw it'a been my experience that an oxy acetylene torch that throws black soot and smoke is running with an acetylene torch valve that isn't opened enough and adjusted properly. I've found that opening the Acet torch valve well beyond "just a crack" to light the torch eliminates completely black soot and smoke...the torch is then adjusted DOWN just to the smoke point...then back up to eliminate any traces of smoke while keeping the flame cone on the tip. A properly adjusted torch with clean tips should throw little to no acetylene smoke... and by following good practices tips rarely, if ever, need to be cleaned...and operate much more efficiently.

On shut down it's a quick turn to close...not slow and smokey... :smoking:
 
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Which of course begs an interesting question....

When is the last time on a CNC cutting machine you saw someone bleed down the regulators, or torches at the end of the shift?

Which begs the next question...what are the manufacturers recommended procedures for shut down and start up of cnc torches? Whatever they are, it's guaranteed there's plenty of places where they aren't followed ;)
 
I don't give a rip what Victor says. No fuel no flame - I shut off the fuel gas first.

I also wind out the regulator handles to give the seats a break when I reopen the cylinders. It only takes a moment to reset them. Especially on 2-stage regulators, which is nearly all I use anymore.

If I shut down the cylinders when I go to lunch, when I come back if the low pressure is still up then sure I just open the cylinders without winding out/back the handles on the regulators. Pressurized = no slam on seat.

I started thinking differently when *I* had to pay for getting my regs repaired. :-)
 
gas shutoff

I was taught to shut off the oxygen first, although
see:
Cutting Torch FAQ - Baker's Gas & Welding Supplies

says they don't care. If the tip was adjusted correctly in the first place you wont see the little carbon feathers all over the shop in the first place. Besides that there is to much noise around us anyway. After suffering with tinnitus for 30 years, I wish that I had done EVERYTHING that I could have to reduce ambient noise.

I had also been taught to unwind the screws in the regulators after I finish using them... but in any two stage regulator there is no way to unload the high pressure knock down section of the regulator. If this causes any wear... I have not noticed it.

I started using Airco 2 stage regulators 40 years ago. I have rebuilt them a few times over the years. I also will buy any one of them that I find at a flea market or automotive tailgate sale, typically buying them for 10 to 20 bucks and add about 25 bucks worth of parts to make them good as new.

The slamming of the seat... as I stated before the first stage is spring loaded all the time by design, you can't unload it and the proper procedure for re pressurizing the regulator is to stand to the side of the possible projectile path of the internal parts and SLOWLY open the high pressure valves on the tanks. This applies to flight path of the gauges also... that being said, I have never seen a regulator come apart. 42 years of construction sites represents a tremendous exposure to abuse of tools by the uncaring soles that work around you every day.

I turn off my tank valves, and leave everything else alone. If the hose and torch de-pressurize in less than a day I start looking for leaks because what's leaking while I'm away is still leaking while I'm using it. You can test your torch valves by simply submerging the tip in water after turning it off (please let it cool off) to verify that the torch valves are holding.
Paul
 
My opinion is if you hear a "pop" then it's burning back into the torch, and that causes soot inside. If it doesn't burn inside the torch, no soot. I always turn off the oxygen first per Victor's suggestions.
 








 
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