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-   -   How many inches of water column will 9lb of gas pressure give? (https://www.askmehelpdesk.com/showthread.php?t=620156)

  • Dec 16, 2011, 02:50 PM
    alevee
    How many inches of water column will 9lb of gas pressure give?
    How many inches of water column will 9lb of gas pressure give?
  • Dec 16, 2011, 03:47 PM
    speedball1
    Quote:

    How many inches of water column will 9lb of gas pressure give?
    Would this be 9 pounds of propane? What's the PSI of the gas? What's the volume of the column of water? If you're asking about head pressure it takes .434 pounds of pressure to lift a column of water one foot. Does that help? Regards, Tom
  • Dec 16, 2011, 04:33 PM
    mygirlsdad77
    Simply multiply the psi by 27.71 to find the inches of water column. So in your case, 9x27.71=249 iwc. I am curious though. Why do you want to know this? Usually measurements in inches of water column are used for extremely low pressures. Either way, that's how you convert it. Hope it helps.
  • Dec 16, 2011, 05:28 PM
    speedball1
    Hey Lee,
    I guess I take things too literal. I was thinking the only gas you can buy by the pound is propane. I should have read the post better. But just a minute here. 249 of what? I come up with a different figure.
    If it takes .434 pounds to lift water one foot wouldn't the math figure out to 9 X .434 =3.906 feet X12 would give you 48.87 inches. Or should I just take a stiff drink and go to bed? Back atchya, Tom
  • Dec 16, 2011, 05:35 PM
    mygirlsdad77
    You might be right Tom. Im looking at it from a psi standpoint of gas supply pressure, like a supply to a natural gas meter. We always use inches of water column to check pressures after the meter, at the furnace, water heater, etc. And the equation I gave is for that type of conversion, which in the ops question worked out to 249 inches of water column. I do a lot of work with natural gas and propane equiptment, mostly furnaces, boilers, water heaters, gas fireplaces etc, so I know this equation is correct for changing gas psi to iches of water column. But now that I look back at the original question, I see he was asking about LBS, not PSI. I might just be way off base now that I think about it. That's why I asked the op what he wanted to know for. We may both be right, or wrong.

    But either way, Ill join you on that stiff drink. Cheers.
  • Dec 17, 2011, 07:07 AM
    speedball1
    Thanks Lee,
    If you've noticed, over the years, I've hung back from answering both gas and combi boiler questions. That's because we don't have combi boilers, furnaced and very little gas installations in my area.
    So I looked at the "9 lbs of gas pressure as 9 PSI of anything. Water, ar, gas or whatever. Sooo!
    You come up with 249 inches of water and I came up with 39.06 inches or 3.255 feet compared to your 249 inches or 20.75 feet. Same question but wildly different answers. Hmmmm!

    You have a great day. Tom

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