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Gauge

Alan (California Radiant) Forbes
Alan (California Radiant) Forbes Member Posts: 4,214
in Strictly Steam
I found this gauge on a steam boiler (1-pipe) which seemed to be running fine. It shows pressure and vacuum, but no indication of units, i.e. ounces, psi.

If psi, I will want to change the gauge or pressuretrol, but don't want to do so needlessly.

Alan


8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab

Comments

  • ratio
    ratio Member Posts: 3,791
    Likely 30 psig, & almost certainly 30 in Hg.
    SWEICanucker
  • Jamie Hall
    Jamie Hall Member Posts: 24,862
    and you need to keep that gauge, even if it doesn't show anything -- the insurance people (and the building inspector) want to have a gauge with twice the pressure relief valve setting. However, it is no problem to install a nice low pressure gauge -- put it on the same pigtail with the pressuretrol or vapourstat.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ChrisJ
    ChrisJ Member Posts: 16,316
    Jamie Hall said:

    and you need to keep that gauge, even if it doesn't show anything -- the insurance people (and the building inspector) want to have a gauge with twice the pressure relief valve setting. However, it is no problem to install a nice low pressure gauge -- put it on the same pigtail with the pressuretrol or vapourstat.

    It's currently showing 29 PSIG.
    I doubt he should keep that one. :)

    It's hard to see in the small picture but does it say WC on the left bottom?

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,214
    It says "VAC."

    Chris said, "It's currently showing 29 PSIG." That's the main thing I was concerned about.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Jamie Hall
    Jamie Hall Member Posts: 24,862
    Alan (California Radiant) Forbes said:

    It says "VAC."

    Chris said, "It's currently showing 29 PSIG." That's the main thing I was concerned about.

    It's busted. But it wouldn't show anything anyway...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ChrisJ
    ChrisJ Member Posts: 16,316
    Jamie Hall said:

    Alan (California Radiant) Forbes said:

    It says "VAC."

    Chris said, "It's currently showing 29 PSIG." That's the main thing I was concerned about.

    It's busted. But it wouldn't show anything anyway...
    Code says a working 30 PSIG gauge.
    Not a broken one stuck at 29 PSIG even when the boiler is off. :)

    I wonder if you removed that gauge and tried to clean it out if it would work. I bet the internal siphon is plugged with rust and crud.

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • neilc
    neilc Member Posts: 2,854
    was thinking the same thing,
    but how did we get to 29?
    that can't be cummulitive,
    known to beat dead horses
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846


    These old bourdon tube gauges have a sector and pinion mechanism that can get out of whack for a variety of reasons, but they're very durable and can usually be fixed, if you can get them apart. With mine, the hard part was getting it off the boiler, It's hard to get a wrench behind the gauge, and then there's always fossilized thread sealant to deal with.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24

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