Announcement

Collapse
No announcement yet.

Bottle Pressure 75/25

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

  • Bottle Pressure 75/25

    For mixed 75/25 gas, how do you know when you need to refill the bottle. Is it at a given pressure or just when it runs out completely? I searched and could not find an answer.

    Thanks
    Dave

  • #2
    Originally posted by Dave I View Post
    For mixed 75/25 gas, how do you know when you need to refill the bottle. Is it at a given pressure or just when it runs out completely? I searched and could not find an answer.

    Thanks
    Dave
    You can safely go down to ~100psi, any lower and you risk drawing off some of the argoff at the bottom of the cylinder. argoff will remove your bead, so be careful as you get close to the century mark.

    Comment


    • #3
      What a stupid answer

      Comment


      • #4
        The problem of running out of shielding gas as your welding is getting a bad weld at that point as it becomes hard to maintain an arc as your arc changes. Pressure to flow meter is set at 35psi for Victor flow meters or 50psi for some Smith flow meters. I don't know what pressure flow gage regulators are set at for various flow rates. Without shielding gas your welds start looking like swiss cheese full of little holes.

        If empty cylinder's valve is left open to atmosphere, water and other contaminates can enter possibly causing rust in cylinder and other problems.

        Comment


        • #5
          I generally keep an eye on the pressure of the bottle. When it gets below about 100 psi, I start thinking of a convenient time to switch out bottles. If I don't have a full spare at the time, I start to keep a very close watch on my welds. At the slightest sign of porosity, I stop. You can weld until the flow is insufficient and porosity starts to develop. The only thing that will suffer is the weld. As long as you close the bottle like normal, there will still be some pressure left in the bottle, so nothing will sneak in. There is no danger of running the bottle too low, like with acetylene.

          Oh, pumpkinhead, thanks for helping the guy out. Oughta get at least one straight answer in before the argoff stuff comes up. Sheesh!

          Dave
          Still building my new old truck - see the progress!
          http://www.ford-trucks.com/forums/65...-coe-idea.html
          http://www.hobartwelders.com/weldtal...ad.php?t=27017

          Square Wave TIG 200 - Woot!
          MM180
          SP125+

          Comment


          • #6
            Thanks for the information guys.

            Comment


            • #7
              You should try welding solid wire with shielding gas off or better yet set your flow rate then turn off shielding gas bottle valve. You then will see what happens.

              Comment


              • #8
                Run the 75/25 tank till it's empty. You will know when it's time to change by the porosity in the weld. Don't give the Gas suppliers anymore of your hard earned cash than you have too!
                Last edited by tommyj3; 01-04-2009, 10:36 AM.

                Comment


                • #9
                  If you are new to your gas flowmeter, some tank pressure gauges are not correct. Sometimes you will run out of gas before the needle hits the peg and sometimes you can weld quite a bit after it is setting on the peg. When my tank is reading low,I will usually pull the trigger and see if my ball or needle is jumping up to its setting before starting a weld. If you can, run the tank empty.
                  Miller Big40
                  Lincoln AC225
                  Hobart Beta Mig 200
                  Victor Senior and Junior oxy/acetylene

                  Comment

                  Working...
                  X