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Thread: Pressure in a closed hydronic system

  1. #21
    Join Date
    Dec 2014
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    Quote Originally Posted by stumpdigger View Post
    I never had a reason to check or bother with a performance curve. Now that I am trying to remember we may have put gauges on pumps 4" and over. Most important was a valved vent on top of volute and ball valve drain with hose bib. Thinking balancer adjusted flow control valves.
    Well I like to measure as much as I can. Example.
    Today had a boiler short cycling.
    Found secondary loop pump running at 45hz off off differencial pressure switch. Measuring by curve and triple duty valve showed about 70 gpm loop flow.
    Boiler measured at 110 gpm.
    On a PS piping system, guess where the extra boiler flow went. Short circuited back to the boiler inlet.
    I could find that with thermometers but measuring flow prooved it.
    Well I guess they both proved each other.
    Per prints, 3way valves added to about 60 gpm so there's the problem. So throttled the boiler flow down, and reprogrammed the setpoints and staging. Ran great after that.
    Being able to work with the skeptical maint man and show proof of my theory, by measuring, was icing on the cake.
    Full flow heating thru 30 VAVs is about 150 gpm so really, often the 110 gpm of the boiler wouldve been too high anyhow.
    Made for my most fun day in a while!

    Sent from my SM-G950U using Tapatalk

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  3. #22
    Join Date
    Dec 2014
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    Quote Originally Posted by stumpdigger View Post
    I guess that I'm getting too old to remember and the brain damage is too difficult to overcome. After six years of not working the skill is just fading away.
    Well shoot! I thought you were still out and about.
    Come out of retirement @stump! Too many good guys retired/retiring.




    Sent from my SM-G950U using Tapatalk

  4. #23
    Join Date
    Feb 2016
    Location
    Louisburg Kansas
    Posts
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    The plant maintenance people use the gages to know when the pump inlet strainer needs cleaned. They are also a good indicator how the system is operating.
    No man can be both ignorant and free.
    Thomas Jefferson

  5. #24
    Join Date
    Jun 2020
    Location
    CHICAGO IL
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    Quote Originally Posted by icy78 View Post
    Well shoot! I thought you were still out and about.
    Come out of retirement @stump! Too many good guys retired/retiring.




    Sent from my SM-G950U using Tapatalk
    My career ended in 2014 when I was coughing up blood everyday. Too many acids, chlorides, asbestos, and hydrocarbons thru my lungs. Have: replaced RT knee, broken rt elbow, busted left wrist, and a plate over left shoulder. I really need a left knee replacement but Corona crap ruined that. I only work when others can't seem to get it.
    " The more I learn the more I realize how much I don't know"

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