I had an Ar CO2 pressure gauge (https://www.amazon.com/dp/B06X3XWVYM/) hooked up to a valve that I was using to control the flow of 95:5 Ar:H mixture. After some overflows (i.e., the needle went to max multiple times), I heard a popping sound and now whenever I open the tank of Ar-H, the pressure immediately goes to maximum and I cannot control the flow rate. Does that mean my pressure gauge is broken or the entire regulator is? Thanks!

PS My regulator + gauge is this one: https://www.airgas.com/product/Gas-E...0aAimCEALw_wcB

  • Just a note, since you don’t know if your regulator is bad I would suggest a flow meter style 24$ a bit further down the page that you linked to the valve. This is what we use in all of our mig and tig machines at the plant. I use a regulator at home like you have been. If you go this route verify your tank valve is the same as the flow meter. There are 2 possible styles that I have seen.
    – Ed Beal
    Oct 7, 2019 at 13:44

2 Answers 2


You have broken it, buy another and get one with a higher maximum so it does not break again.

It has either broken or popped the Bourdon tube or cracked / broken the gearing...

  • 1
    What's "it"? The regulator or the guage?
    – Akimbo22
    Oct 6, 2019 at 8:15
  • Also, if the valve that turns the regulator is working just fine, does that mean the gearing is too? Can I just replace the Bourdon tube as opposed to buying a new regulator?
    – Akimbo22
    Oct 6, 2019 at 8:16
  • The reason the gauge was damaged was due to excessive pressure, back the adjusting screw /knob all the way out if you still have pressure on the low pressure gauge see my answer.
    – Ed Beal
    Oct 6, 2019 at 19:10
  • I don't have pressure on either gauges
    – Akimbo22
    Oct 6, 2019 at 19:37
  • The high pressure gauge should show bottle pressure when the tank valve is opened. The low pressure gauge only what the regulator Is allowing to pass. Did you leave your bottle on or open and The tank leaked down?
    – Ed Beal
    Oct 7, 2019 at 13:29

It’s not that you have broken it. the diaphragm in the regulator failed, this happens and since it is just a forming gas you can get a rebuild kit for the regulator much cheaper than a new regulator in most cases. You may have damaged the low pressure gauge, these are usually 0-25 on the equipment at my plant ant you were hitting it with up to 2000 psi. Lucky since it’s not O2 no special equipment or cleaning is needed but things do need to be clean.

  • So do you think the next thing to do would be to replace the gauge and see if that fixes the problem?
    – Akimbo22
    Oct 6, 2019 at 19:37
  • If you frapped the gauge it is toast. They can be repaired for very high end gauges but the calibration in never quite right. Low pressure gauges are easily damaged, I would verify the pressure was not cranked up two high. And the regulator is working before putting a new gauge on or the same will happen to your new gauge.
    – Ed Beal
    Oct 7, 2019 at 13:34

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