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Thread: Using Check Valve to plug lines?

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    Join Date
    Aug 2016
    Annapolis, MD

    Using Check Valve to plug lines?

    A previous pool person closed our pool last year using two of these check valves to plug our lower return lines. The up-side is they are easy to blow the lines - just attach it and pump air through it. It shuts off the back-flow by itself.

    I'm a little leery of using them without knowing for sure if they'll hold up to the rigors of a Maryland mid-winter cold-snap. They did work last year, but I don't want to assume that means they'll always work.

    Anyone ever use these instead of rubber plugs?

    check valve.jpg
    10K gal; AG vinyl; Haywood DE2420 24 sqft DE filter; 1 HP Haywood Power-Flo LX; Haywood H1000ID Heater; skimmer, main drain & 3 returns; city water; TF100XL

  2. Back To Top    #2
    JoyfulNoise's Avatar
    Join Date
    May 2015
    Tucson, AZ

    Re: Using Check Valve to plug lines?

    Well, if it worked last year then I suppose it can work again this year. As long as the check valve seal looks to be in good shape and the internal spring isn't corroded or anything like that, it should work fine. I would definitely replace the teflon tape on the threads though.
    16k IG PebbleTec pool, 650gal spa, spillway and waterfall, 3HP IntelliFlo VS / 1.5HP WhisperFlo, Pentair QuadDE-100 filter, IC40 SWCG, MasterTemp 400k BTU/hr NG heater, KreepyKrauly suction-side cleaner, EasyTouch controls, city water, K-1001, K-2006 and K-1766 test kits, Mannitol test for borates

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    Mod Squad JVTrain's Avatar
    Join Date
    Feb 2014
    Central Minnesota

    Re: Using Check Valve to plug lines?

    I'd agree here. There are also plugs sold for winterizing called "duck plugs." Winter Duck Plug (fits 1-1/2" Threads): Anderson Manufacturing Company, Inc.

    I'd trust a standard PVC check valve or a solid expandable plug more than I would these duck plugs. I assume by "lower returns" you mean that they will remain underwater after closing? Verify they still work and you should be fine.
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

  4. Back To Top    #4

    Join Date
    May 2013
    Long Island NY

    Re: Using Check Valve to plug lines?

    Those would prevent me from ever being able to blow out the main drain and create an air lock.
    19,000 gal - Vinyl IG - Sand filter -1.5hp. - Taylor k 2006 - Loop Loc cover

  5. Back To Top    #5
    ship of fools's Avatar
    Join Date
    Nov 2011
    Albany, NY

    Re: Using Check Valve to plug lines?

    I used the duck plug with no issue. I only used it on the last return.

    There isn't much pressure on them from the small amount of water they are holding back. If they were down 10' i would be more concerned.
    21,000 gallon inground
    Haywood Sand Filter
    Vinyl Liner

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