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  1. #1
    650b me
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    Recommended PSI from regulators to torch

    Oxygen?
    Acetylene?

    I've reviewed all of my notes from UBI and I don't have anything on this. I know it was really low, like 5-10 psi?

    The fact that I'm asking means that I'm finally set up to braze frames at home. Just got my tanks and assorted brass goodies yesterday.

  2. #2
    Randomhead
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    5 psi should work

    I have no idea what mine are set at to be perfectly honest

  3. #3
    650b me
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    Thanks, U. After viewing some OA videos on YouTube, I just tried test-firing my torch.

    As soon as I open the valve on the oxygen tank, I can hear gas escaping through what I believe is called the relief valve, located in about the 4 o' clock position as I view the gauges on the regulator. I don't think this is normal, so I aborted the process and closed the valve immediately. Any thoughts?

  4. #4
    Randomhead
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    no, never had that happen. Are they new? Those valves are there in case the pressure in the torch is higher than the regulator is set for.

  5. #5
    650b me
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    Not new. I bought it used in 'very good condition' on eBay. Here's a photo from the eBay listing:

    Recommended PSI from regulators to torch-victor-vts-250a.jpg

    It's a Victor VTS 250A. Relief valve is on the lower right below the T handle.

  6. #6
    dru
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    I've got Victor regs too, and you shouldn't be hearing gas escape from that valve. When you turn everything on and purge the lines then close the torch valves you should hear silence.

    When you are opening the O2 tank valve you have your reg screw valve backed off counterclockwise, right? If this is the case you shouldn't hear a thing either and the only thing that should happen is seeing a few thousand psi on the right gauge and zero on the other.

    As for PSI it also depends on line length. If you are running 50 feet like me, you need a bit more psi at the reg to get the correct amount at the torch.

    Make sure you never come near 15 psi on your acetylene.

    Drew
    occasional cyclist

  7. #7
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    People told me 5 for acetylene and 20ish for O2 so I've been running that. Seems to do the trick.

  8. #8
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    Quote Originally Posted by dru View Post
    When you are opening the O2 tank valve you have your reg screw valve backed off counterclockwise, right? If this is the case you shouldn't hear a thing...
    Drew
    Correct, the reg valve is backed off CCW until it's so loose it jiggles. Oxygen is definitely escaping out the relief valve.

    Tomorrow I will call the LWS where I bought my cylinders and see if they can help me. Thanks everyone.

  9. #9
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    Quote Originally Posted by adarn View Post
    People told me 5 for acetylene and 20ish for O2 so I've been running that. Seems to do the trick.
    what torch tip size and brand do you use at these settings? Thanks, Brian

  10. #10
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    Harris, I like #0 for fillets #2 for "lug brazing" which I only do with brass for bi-lam stuff i.e. seat tube sleeves.

  11. #11
    Who turned out the lights
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    As a somewhat related question, at what PSI in your O2/Acet tanks do you stop using them and take them back to the LWS for exchange/re-fill? I have not had to do that yet, and just can't remember where I had those numbers written down. I'm not approaching it, but want to remember it for when it happens.

  12. #12
    dru
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    You can run the acetylene down to 15 or 20 psi no problem. If you do run it out the acetone burns purple. As for o2, again low like under 100 psi. I've ran them low enough that the flame starts carburizing.

    Drew
    occasional cyclist

  13. #13
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    Quote Originally Posted by dru View Post
    If you do run it out the acetone burns purple.

    Drew
    Acetone? You mean acetylene, right?

  14. #14
    dru
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    No, I mean acetone. Acetylene is chemically very unstable which is why you should never exceed or come near 15 psi gas pressure. Your acetylene tank keeps the gas stable at 200 psi or so because the acetylene is dissolved in acetone. This is why you should never knock over your tank while it is on as liquid acetone will come out into your regs. and lines. Tanks should always be stored upright although having one on its side while off isn't going to do anything bad.

    Drew
    occasional cyclist

  15. #15
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    Good to know, thanks. Acetone is a carcinogen, correct? I can't imagine burning it would be a good thing.

  16. #16
    dru
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    If you are burning up the acetone it will have the same combustion products as pretty much any other hydrocarbon; co2, h20, and co if combustion is incomplete.

    Acetone is nail polish remover. I used to work with it in a chemical plant. Bad for sure, but there is much worse stuff.

    The torch and equipment isn't designed to burn it which is why I mentioned the purple flame. That way you know to stop.
    occasional cyclist

  17. #17
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    I just had this conversation with a high end welder at work. He insisted that I should use 14 acetylene and 40 o2. I have not cranked it up that high, but am currently about 12/30. I was running about 5 acetylene and 15 o2 with a 0 tip. I must say my flame is much more stable now - meaning the mix does not drift as I am working. He is suggesting that I use a turbo torch (acetylene/air) for lug silver brazing, but I have not tried it yet.

  18. #18
    Harrumph
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    5psi Acetylene and 10 O2 is what I've been using, based on minimal experience and internets advise. Anything above 10-15psi has never even been on the radar.
    Slowly slipping to retrogrouchyness

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