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  • Newbie startup questions

    Hi guys,

    I was given an oxy acetylene setup and would like some advice about getting started with it. I used oxy acetylene a bit in college but only to fire it up and do stuff, not work with the tanks and connections. I'd like any advice about firing this up safely.

    The acetylene tank is 35 cu ft. It says B Acetylene on the bottle, along with the following: UN 1001, TW26-4, B-5702BB. It has a Harris regulator model 25 15.

    The oxygen tank is (I was told) 40 cu ft. It's labeled UII1072, TC-3AAM154, DOT-3AA2015, M8004, REE45.4, 1301800, O2(up arrow symbol)00+(star symbol). It has a Harris regulator model 25-100C.

    Are any of those numbers important to me? Do the bottles need a safety check? Is there a way to tell how much is in the bottles? Also when they run out do I just get them refilled at the local welding supply?

    It has about 12' of hose. The person I got it from said that the hose was old and they recommended replacing it. It also came with a Harris torch H-16-E model 16 and a Harris 1 tip and a Smith NE180-1 tip.

    Any advice you have about getting started with this is appreciated! I would eventually like to get set up to gas weld and cut and am hoping that this will help to start me on that path.

  • #2
    Originally posted by jsw View Post
    Hi guys,

    I was given an oxy acetylene setup and would like some advice about getting started with it. I used oxy acetylene a bit in college but only to fire it up and do stuff, not work with the tanks and connections. I'd like any advice about firing this up safely.

    The acetylene tank is 35 cu ft. It says B Acetylene on the bottle, along with the following: UN 1001, TW26-4, B-5702BB. It has a Harris regulator model 25 15.

    The oxygen tank is (I was told) 40 cu ft. It's labeled UII1072, TC-3AAM154, DOT-3AA2015, M8004, REE45.4, 1301800, O2(up arrow symbol)00+(star symbol). It has a Harris regulator model 25-100C.

    Are any of those numbers important to me? Do the bottles need a safety check?
    The bottles are retested and certified every 5 years before they are refilled. You don't need to worry about it right now. The filler will tell you when they need to be tested.

    Is there a way to tell how much is in the bottles?
    When you put the regulators on, the higher pressure gauge will show what's in the bottle. A full bottle of O is about 2000 psi and a full A is about 300 pounds, but this depends on the temperature and can vary somewhat.

    Also when they run out do I just get them refilled at the local welding supply?
    Hopefully. It depends on where they came from and who owns them. More than likely, you can take them to a LWS and get them filled.

    It has about 12' of hose. The person I got it from said that the hose was old and they recommended replacing it. It also came with a Harris torch H-16-E model 16 and a Harris 1 tip and a Smith NE180-1 tip.

    Any advice you have about getting started with this is appreciated! I would eventually like to get set up to gas weld and cut and am hoping that this will help to start me on that path.
    Replace the hose. Be sure that the fittings inside the valves on the bottles are clean. (turn the bottle on for a second to clean them) Attach the regulators to the bottles. The O is right handed and the A is left handed thread. Before turing on the bottles, turn the handles on both regulators to the LEFT until they turn easily but don't unscrew them completely out. Turn on both bottles. Now, turn the regulator handles to the right until the low pressure gauges start to move. Set the O to around 40 psi and the A to around 8 psi. This should be okay for starters.

    Okay, now the warnings. Pay attention to this part.... NEVER set the Acetylene to more than 15 psi. It becomes unstable above that. NEVER use any oil of any kind on the regulators. Both of the above are cardinal rules and must be obeyed.

    You should be able to crack the A valve on your torch and light it. Open the O valve slowly until a nice blue flame is achieved. You are ready to start now.
    Jim

    Miller MM 210
    Miller Dialarc 250P
    Airco 225 engine driven
    Victor O/A
    Lots of other tools and always wanting more

    Comment


    • #3
      I can't post anything more than Jim has said. I also second getting a new hose. They don't cost very much. If you look on these forums using the search function, you will find most of this also some links to videos for using the torch.

      Good luck, be safe and have fun!
      Miller 140 A/S
      HF Flux Core
      Dewalt Chop Saw
      Smith O/A Torch
      Ryobi Grinder, Craftsman & HF Grinders

      Harley Electra Glide Classicsigpic

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      • #4
        Thanks Jim!

        Are the hoses all standard or are there different sizes and quality? I thought I'd heard someone say to make sure and get the right size for the tank connection. Also do you recommend getting backflow preveters and/or flashback arrestors with the hose?

        Thanks

        Comment


        • #5
          Your hoses should have B size swivel nuts which is most common size. Little tiny torches have small hoses with A size swivel nuts.

          There is a better grade hose available that withstands Propane better than standard hose.

          Check valves and flash back arrestors are standard required by osha ... and a good idea. They are usually combined.

          What is your hose inside diameter and length?

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          • #6
            There is no test that can determine the condition of hoses other than visual inspection and age. If hose has cracks, cuts, bulges or leaks then you decide if they are ok or should be repaired or replaced. Your liability. Repair is cutting out bad section often at torch end.

            Comment


            • #7
              Originally posted by Jim-Tx View Post
              Before turing on the bottles, turn the handles on both regulators to the LEFT until they turn easily but don't unscrew them completely out.
              I was at local welding supply when young engineer from navy base brought in regulator with damaged LP gage that he said was free flowing. I think he shut the regulator like a valve and opened bottle valve. He might have even damaged the regulator. He thought his education gave him needed knowledge without getting readily available help. Then didn't want anyone to know about his mistake.

              Comment


              • #8
                All the advice you have been given so far is excellent for cutting, and below is some advice to add to it that will help if you intend to do welding or brazing.

                Balancing Gases In OAW

                Back in the” old days”, before the widespread use of check valves and flashback arrestors, beginners were always taught to balance gases. This is a procedure I still use today, not only because of safety, but because it is a good way to check on the current condition of your equipment, and guarantees the correct setting with any tip size or regulator gauge peculiarity. With a little practice, it only takes a minute, and accurately gives you the proper setting with any make of equipment, with the max. and min. of the heat range of any tip. The instructions I usually give an OAW beginner are below.

                With both bottles on, and regulator adjusting screws turned out (“off” position), turn the acetylene torch valve wide-open (3 half turns is usually enough). Then, turn your acetylene regulator adjusting screw in until gas starts to flow and light the torch. Continue to turn the adjusting screw in until the flame just blows away from the tip, then back off the screw until the flame just returns to the tip. Your acetylene pressure is now set for that tip.

                Then , open the oxygen torch valve wide-open (3 half turns) and slowly begin to turn your oxygen regulator adjusting screw in until you you have a blue feather extending from a blue cone at the tip. Continue to add oxygen until the feather just disappears into the inner cone, giving you a neutral flame. You now have the torch set for maximum heat for that tip. (Wiggle both torch valves at this point to make sure you have them wide-open: if you do the flame will not change)

                Finally, turn your oxygen torch valve off. Then, close your acetylene torch valve until the yellow flame starts to produce smoke, and immediately open it just so it is not smoking. Slowly open your oxygen torch valve until you again have a neutral flame , and you now have the minimum flame you can use on that tip without backfires.

                The safety factor created by using this procedure is that both gases are at equal pressure when you are done, so that it is impossible for either gas to back up into the other line to cause a flashback.

                This seems like a lot of trouble, but only takes 1-2 minutes with practice and only needs to be done once unless tips or regulator settings are changed. Also, note that at no point are you depending on or even looking at regulator gauges, which can be very unreliable when abused. This method will work with all standard OA equipment for welding.

                Comment


                • #9
                  Another question

                  Thanks for all the advice! I got some new hoses and flashback arrestors and got this running over the weekend. Everything seems to run fine (although I'm very rusty...). The oxygen regulator buzzes when oxygen is flowing through it though. It doesn't happen at really low flow but when I turn it up there is an audible buzz and the needle vibrates. It doesn't go totally crazy but it doesn't seem right. I also noticed a small amount of corrosion on that regulator (on the inlet from the tank). Is that something to be concerned about & if so what do y'all suggest?

                  Comment


                  • #10
                    All regulators buzz slightly in normal operation, and this should stop as soon as you stop the gas flow. However, the needles should not vibrate. Since this is occurring, it may be that the diaphragm in the regulator is stiff and not responding quickly enough to maintain pressure (I assume that it is the hose pressure gauge needle that is vibrating) or, the poppet valve attached to the diaphragm may be sticking slightly.
                    Does the flame vibrate when this is occurring? What pressures are you using, and are you welding or cutting?

                    If the corrosion is not enough to affect the integrity of the metal, (eg just marring the surface finish) I would clean with crocus cloth and forget it. If it is more serious, you might consider replacing the tube.

                    Below you should find a diagram illustrating regulator operation FYI

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