Acetylene & Oxygen Tank blues

Guys, I'm having a hell of a time. My gas torch tanks keep leaking out somehow. I make it a positive point to turn off the main tank valves when finished. Now, the tanks are on an exchange program, so the tanks get swapped out for different ones when I go for a refill. I can understand if I was dealing with the same tank everytime, but I'm not. This is a portable torch set, so it has the smaller tanks (20cf oxy & 10cf acy ). New tanks were last installed in july, torch was used 1 time to cut off exhaust system, then put away. This morning I went to use it and yep, empty. So do you guys think there is a problem, or do you think I am expecting too much out of the small tank system? Soapy water test done about 4 times and no visible bubbles. I have been getting tanks from Tractor Supply store.

That main valve should shut it off tight. The only time we have had a loss of the gas is when we forget to turn off that main one. Since you are swapping out tanks each time it seems to rule out a valve problem, unless, unknown to you, they are simply refilling yours and giving it back to you. Those small tanks don't hold much, so you are probably just using more than you thought.

Don

I had one tank from my supplier that had a valve to body leak - it went 'dry' in less then a week. They replaced it free, but the 45 minute trip to their store po'd me tho

Those tanks should give you about 20 minutes run time with a oo tip in your cutting torch and a hour with a o in your welding torch @ 5 and 15 psi. Bigger tips and higher pressures will require bigger tanks They will not go flat with the tanks shut off under normal circumstances. Did you blow out the valves before fitting the regulators? Do the test agin using Ivory liquid soap @ 1 tablespoon soap to 1 pint water. Pay particular attention to the area around the valve stems and packings with the tanks closed then again with them fully opened and backseated. The quarter turn deal is no longer valid unless your tanks are over 20 years old.
You may want to have the local welding supply house check and refurbish the seats on the regulators if they have been damaged. You would be surprised at how fast tanks empty with just a small leak in that area because that is unregulated pressure.

Don't rule out one or more of your "buddies" slipping in there to leak them down. Some people have a wierd sense of humor.

The more I think about this one, the more I bet he just used more gas doing those chores than he thought. We have progressively moved up to bigger and bigger tanks over time, we kept running out at the worst times (Sunday at 5 pm usually, when everything is closed:mad:). I think our tanks are now called a number 4 size and they last a long time. We usually keep a spare oxygen tank filled waiting too as that seems to be the one that runs out first every time.

Don

You sure don't want that stuff leaking out! The last tank of acetylene I bought was over 80 bucks, up from the previous 39. Some BS about one of three factories that make the stuff closing down, was the excuse.