Announcement

Collapse
No announcement yet.

Possible High Pressure Oxygen Cylinder Malfunction??? Help!?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Possible High Pressure Oxygen Cylinder Malfunction??? Help!?

    So a couple days ago (2/11/20) I changed out a high pressure oxygen bottle on an oxy/acetylene torch. When I did the pressure registered on the regulator at 2000 psi. Today (2/13/20) as I was going through the lab and checking all the bottle pressures this cylinder (which should be close to full since I just changed it) wouldn't register a pressure on the high pressure gauge but it would register on the working gauge when dialed in. Thinking there was something wrong with the regulator I swapped it out with a brand new one, but it did the same thing. Registered zero on the cylinder pressure gauge but still registered pressure on the working side when I dialed it in. After that I tried putting the original regulator (the one I thought was broken) on a different bottle and it worked perfectly fine.

    Since it clearly isn't a problem with the regulator either I'm attaching the regulator wrong on that bottle somehow or there is some problem with the bottle itself. I've spent the better part of the morning on google and digging through various instruction manuals but I can't seem to find this problem listed anywhere.

    The torch seems to be working fine, and my professor said to go ahead and let the students use it (I am a welding student working in the school welding lab) but I'm a little concerned about letting students use it. Anyone have any advice or has encountered this problem before? Since this is a school all our machines and tools undergo some pretty rough use from students just learning how to use things, but this is a problem no one here has encountered before.

    Thanks!

    Edit 1: It was checked for leaks (and is checked for leaks every time a bottle, regulator, or hose is replaced/changed out)
    The pictures in this post were taken with the oxy valve open all the way.

    In the photos it shows the working gauge at about 40 psi, but I just went back and tried to see how high I could dial in the working side, got it all the way almost to 200 psi (the max on the gauge) before it became too hard for me to turn.

    Edit 2: I asked another professor when he got in and showed him some of the comments and he think's one of the students probably left it open overnight. Classes just started here, so the students are still getting the hang of things. I'll make sure to tell the night classes to check the torch cutting stations and remind their students to put them away better. Thanks guys!!
    Last edited by Welding.Whimsy; 02-13-2020, 11:33 AM.

  • #2
    If I had to offer a few suggestions, I'd suggest the cylinder valve wasn't fully opened to reseat the valve and leaking around the valve stem, or I'd say the cylinder to regulator gland nut attachment point was leaking from not being tightened adaquetly. Sounds like the cylinder is below what the high pressure side will show in reading. Was it checked for leaks, you don't mention doing so. Was the cylinder valve fully opened when in use? You don't mention that?

    You could screw in the adjusting screw and see how high the pressure will register on the low pressure side, but it sounds like from what you have mentioned, it's leaked to the atmosphere, below the 400psi or so it takes to show on the high pressure side, while retaining enough pressure for a while to operate.

    Shame on your instructor who's job it is to do such work for liability reasons, failing to over see and check such if being performed by the student under the guise of learning, and not fully explaining how such could occur to you and the other students.

    Comment


    • #3
      Sounds like it leaked.
      --- RJL ----------------------------------------------

      Ordinarily I'm insane, but I have lucid moments when I'm merely stupid.
      -------------------------

      Comment


      • #4
        Originally posted by oldguyfrom56 View Post
        If I had to offer a few suggestions, I'd suggest the cylinder valve wasn't fully opened to reseat the valve and leaking around the valve stem, or I'd say the cylinder to regulator gland nut attachment point was leaking from not being tightened adaquetly. Sounds like the cylinder is below what the high pressure side will show in reading. Was it checked for leaks, you don't mention doing so. Was the cylinder valve fully opened when in use? You don't mention that?

        You could screw in the adjusting screw and see how high the pressure will register on the low pressure side, but it sounds like from what you have mentioned, it's leaked to the atmosphere, below the 400psi or so it takes to show on the high pressure side, while retaining enough pressure for a while to operate.

        Shame on your instructor who's job it is to do such work for liability reasons, failing to over see and check such if being performed by the student under the guise of learning, and not fully explaining how such could occur to you and the other students.
        Checked for leaks? We spray the regulator to cylinder connectors (not sure proper terminology, still learning sorry! This is only my second semester!) with a micro leak detector every time we change the bottles, regulators, or hoses. Is that what you mean or is there a different leak checking method?

        I opened the oxy cylinder completely when I tried to check the pressure today, so I don't think it's because it wasn't opened enough.

        I just went back and tried to see how high I could dial in the working side, got it all the way almost to 200 psi (the max on the gauge) before it became too hard for me to turn.

        EDIT: I asked another professor when he got in and showed him some of the comments and he think's one of the students probably left it open overnight. Classes just started here, so the students are still getting the hang of things. I'll make sure to tell the night classes to check the bottles and remind their students. Thanks guys!!
        Last edited by Welding.Whimsy; 02-13-2020, 11:12 AM.

        Comment


        • #5
          Cylinder leaked down.... At low pressure in cylinder high pressure gauge become very inaccuracy, that is why low pressure gauge registers but high pressure does not.... When you opened cylinder valve did you open fully and then check for leak at stem of handle, most high pressure valves are double seal meaning it also seal when valve is seated full open ( only acetylene tanks do not fall in this category) .... NOt opening valve completely will possibly allow pressure to bleed off at stem of valve...

          Dale


          Last edited by Dale M.; 02-13-2020, 11:13 AM.
          "Fear The Government That Wants To Take Your Guns" - Thomas Jefferson..

          Comment


          • #6
            I tend to agree that the thing leaked down overnight.

            I dunno if things have changed...….but I've always found it to be good practice to shut the valve on the cylinder when the rig isn't being used for any appreciable time......including while working with it intermittently during the work day. Regulators leak, hose connections leak, and cylinder valves can leak. Lose a half bottle of Acetylene, and you'll learn yer lesson

            To really leak test the rig...…….use a cylinder with good pressure. Open the valve ALL THE WAY (old school way because the packing used to have to be fully seated open or closed). I never run my stuff with a half open O2 valve. Acetylene should never be run all the way open......if you need to shut the gas off in a hurry...……..less turns the better.

            Anyways...….once you've opened the cylinder to "charge" the system. Shut the valve. Look at the gauges, and see if pressure drops over time. This tells ya that ya gotta leak downstream. Your low side pressure should be adjusted for cutting when doing this. You need gas all the way from the cylinder to the torch. 2000psi high side/30psi low side. This should hold over time.

            Little side note here...…………….I've seen more torch handles ruined because the guys crank down hard on the valves. Never do this. The gas should be shut off just fine with a gentle turn on the valve knob. I gotta 20yr old Harris torch that still seals like new, mainly because I don't mistreat it.

            Another side note (this is gettin' to be a novel)…...Don't tighten the crap out of the regulator attaching nut! I get about 50% of my bottles that I've swapped out THAT HAVE F'D UP CGA SEATS The previous moron overtightened the regulators, ruined his regulator tip, and ruined the cylinder seat. THEN I GOTTA ALMOST RUIN MY REGULATOR TIP TO KEEP IT FROM LEAKING. If I find that it's gonna take a 4 foot cheater bar to tighten the regs on the bottle...……….I just use somewhat more-than-proper torque, and make sure to turn the bottle off after cutting. PITA, but it is what it is.

            Rant over

            Comment


            • #7
              Originally posted by Welding.Whimsy View Post

              Checked for leaks? We spray the regulator to cylinder connectors (not sure proper terminology, still learning sorry! This is only my second semester!) with a micro leak detector every time we change the bottles, regulators, or hoses. Is that what you mean or is there a different leak checking method?

              I opened the oxy cylinder completely when I tried to check the pressure today, so I don't think it's because it wasn't opened enough.

              I just went back and tried to see how high I could dial in the working side, got it all the way almost to 200 psi (the max on the gauge) before it became too hard for me to turn.

              EDIT: I asked another professor when he got in and showed him some of the comments and he think's one of the students probably left it open overnight. Classes just started here, so the students are still getting the hang of things. I'll make sure to tell the night classes to check the bottles and remind their students. Thanks guys!!


              Yes, that's what I mean by checking for leaks. Using an approved leak test solution. As far as checking the connections, in theory, even if the cylinder valves are left open, the system shouldn't leak.

              It would suggest then that the student didn't close the cylinder valve, and possibly, either A) closed the acetylene off first and failed to close the oxygen valve on the torch handle after seeing the flame diminished, B) the oxygen valve on the torch handle is leaking by not fully sealing closed, C) it might also be leaking else where from the regulator to the torch handle.

              Looking at your picture after I downloaded it for a close up, it appears a cutting attachment is in place as well check valves.​ Pressure the system, valves closed, test again and remember that just because it doesn't leak around the torch valve, or connections, length of hose, it could still leak past the torch valve if it's not seating shut allowing gas out the end of the torch tip.

              You might incorporate a system to mark daily consumption rates. Like your notice on the cylinder, how much registers at the start and finish helps forecast use and cost to operate a welding program. As well, it assists in attaching a degree of responsibility and accountability to those using the equipment.

              Comment


              • #8
                Originally posted by Dale M. View Post
                Cylinder leaked down.... At low pressure in cylinder high pressure gauge become very inaccuracy, that is why low pressure gauge registers but high pressure does not.... When you opened cylinder valve did you open fully and then check for leak at stem of handle, most high pressure valves are double seal meaning it also seal when valve is seated full open ( only acetylene tanks do not fall in this category) .... NOt opening valve completely will possibly allow pressure to bleed off at stem of valve...

                Dale

                I would agree that a cylinder-valve seat is probably responsible, in the fully-open or fully closed condition, or, a faulty relief-valve, since you checked all other connections with leak -detector. Meanwhile. the cylinder should be replaced, moved out-doors, and your supply company asked to deal with it.

                Comment

                Working...
                X