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Expansion Tanks

  • #30 Extrol Expansion Tank (4.4 Gallon) Product Image
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    #30 Extrol Expansion Tank (4.4 Gallon) 102-1 #30 Extrol Expansion Tank (4.4 Gallon)
    SKU: 102-1
    Brand: Amtrol
    (223)
    $33.49 each
    $128.76 box of 4
    $32.19 each
    4,865
    Fri, Oct 25
    4,865
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    4,865 Fri, Oct 25
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  • #15 Extrol Expansion Tank (2 Gallon) Product Image
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    #15 Extrol Expansion Tank (2 Gallon) 101-1 #15 Extrol Expansion Tank (2 Gallon)
    SKU: 101-1
    Brand: Amtrol
    (58)
    $29.29 each
    $112.76 box of 4
    $28.19 each
    1,492
    Fri, Oct 25
    1,492
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    1,492 Fri, Oct 25
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  • #60 Extrol Expansion Tank (7.6 Gallon) Product Image
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    #60 Extrol Expansion Tank (7.6 Gallon) 103-1 #60 Extrol Expansion Tank (7.6 Gallon)
    SKU: 103-1
    Brand: Amtrol
    (29)
    $65.85 each
    $253.00 box of 4
    $63.25 each
    698
    Fri, Oct 25
    698
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    698 Fri, Oct 25
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  • 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain Product Image
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    1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain 41672 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain
    Contains Lead
    SKU: 41672
    Brand: Webstone
    (9)
    $22.29 each
    $213.90 box of 10
    $21.39 each
    243
    Fri, Oct 25
    743
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    243 Fri, Oct 25
    500 Mon, Oct 28 – Tue, Oct 29
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  • 11" HydroClaw Expansion Tank Support Bracket Product Image
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    11" HydroClaw Expansion Tank Support Bracket HC11-A 11" HydroClaw Expansion Tank Support Bracket
    SKU: HC11-A
    Brand: Storm King Enterprises
    (43)
    $40.95 each
    136
    Fri, Oct 25
    136
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    136 Fri, Oct 25
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  • QuickStrap Expansion Tank Mounting Bracket <br>(2.5 Gal. Capacity) Product Image
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    QuickStrap Expansion Tank Mounting Bracket (2.5 Gal. Capacity) QS-5 QuickStrap Expansion Tank Mounting Bracket (2.5 Gal. Capacity)
    SKU: QS-5
    Brand: Holdrite
    (27)
    $14.99 each
    $143.90 box of 10
    $14.39 each
    116
    Fri, Oct 25
    116
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    116 Fri, Oct 25
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  • QuickStrap Expansion Tank Mounting Bracket<br>(5 Gal. Capacity) Product Image
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    QuickStrap Expansion Tank Mounting Bracket (5 Gal. Capacity) QS-12 QuickStrap Expansion Tank Mounting Bracket (5 Gal. Capacity)
    SKU: QS-12
    Brand: Holdrite
    (27)
    $16.99 each
    $162.90 box of 10
    $16.29 each
    138
    Fri, Oct 25
    138
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    138 Fri, Oct 25
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  • Flexconsole - 1/2" x 1/2" NPT - Steel (Red) Product Image
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    Flexconsole - 1/2" x 1/2" NPT - Steel (Red) 97975 Flexconsole - 1/2" x 1/2" NPT - Steel (Red)
    Contains Lead
    SKU: 97975
    Brand: Flamco
    (7)
    $22.95 each
    221
    Fri, Oct 25
    221
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    221 Fri, Oct 25
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  • 8" HydroClaw Expansion Tank Support Bracket Product Image
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    8" HydroClaw Expansion Tank Support Bracket HC8-B 8" HydroClaw Expansion Tank Support Bracket
    SKU: HC8-B
    Brand: Storm King Enterprises
    (24)
    $30.95 each
    54
    Fri, Oct 25
    54
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    54 Fri, Oct 25
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  • Model 110 Fill-Trol<br>w/ Valve (4.4 Gallon) Product Image
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    Model 110 Fill-Trol w/ Valve (4.4 Gallon) 110-1 Model 110 Fill-Trol w/ Valve (4.4 Gallon)
    SKU: 110-1
    Brand: Amtrol
    (36)
    $75.99 each
    $291.96 box of 4
    $72.99 each
    153
    Fri, Oct 25
    153
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    153 Fri, Oct 25
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  • ETX-30, Non-Potable Water Expansion Tank<br>(4.5 Gallon) Product Image
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    ETX-30, Non-Potable Water Expansion Tank (4.5 Gallon) 0066606 ETX-30, Non-Potable Water Expansion Tank (4.5 Gallon)
    SKU: 0066606
    Brand: Watts
    (12)
    $37.99 each
    $364.90 box of 10
    $36.49 each
    123
    Fri, Oct 25
    123
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    123 Fri, Oct 25
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  • SX-30V Extrol Expansion Tank (14 Gallon) Product Image
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    SX-30V Extrol Expansion Tank (14 Gallon) 118-27 SX-30V Extrol Expansion Tank (14 Gallon)
    SKU: 118-27
    Brand: Amtrol
    (7)
    $129.99 each
    $374.97 box of 3
    $124.99 each
    121
    Fri, Oct 25
    121
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    121 Fri, Oct 25
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  • RX-30 Radiant Extrol Expansion Tank<br>(4.4 Gallon) Product Image
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    RX-30 Radiant Extrol Expansion Tank (4.4 Gallon) 141-305 RX-30 Radiant Extrol Expansion Tank (4.4 Gallon)
    SKU: 141-305
    Brand: Amtrol
    (10)
    $62.99 each
    $239.96 box of 4
    $59.99 each
    83
    Fri, Oct 25
    83
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    83 Fri, Oct 25
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  • Model 109 Fill-Trol<br>w/ Valve (2 Gallon) Product Image
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    Model 109 Fill-Trol w/ Valve (2 Gallon) 109-1 Model 109 Fill-Trol w/ Valve (2 Gallon)
    SKU: 109-1
    Brand: Amtrol
    (17)
    $69.95 each
    $268.60 box of 4
    $67.15 each
    125
    Fri, Oct 25
    125
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    125 Fri, Oct 25
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  • SX-40V Extrol Expansion Tank (20 Gallon) Product Image
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    SX-40V Extrol Expansion Tank (20 Gallon) 118-78 SX-40V Extrol Expansion Tank (20 Gallon)
    SKU: 118-78
    Brand: Amtrol
    (10)
    $164.95 each
    $475.05 box of 3
    $158.35 each
    112
    Fri, Oct 25
    112
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    112 Fri, Oct 25
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  • #90 Extrol Expansion Tank (14 Gallon) Product Image
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    #90 Extrol Expansion Tank (14 Gallon) 112-1 #90 Extrol Expansion Tank (14 Gallon)
    SKU: 112-1
    Brand: Amtrol
    (10)
    $114.95 each
    $441.40 box of 4
    $110.35 each
    113
    Fri, Oct 25
    113
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    113 Fri, Oct 25
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  • SX-60V Extrol Expansion Tank (32 Gallon) Product Image
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    SX-60V Extrol Expansion Tank (32 Gallon) 118-79 SX-60V Extrol Expansion Tank (32 Gallon)
    SKU: 118-79
    Brand: Amtrol
    (1)
    $205.99 each
    $391.98 box of 2
    $195.99 each
    75
    Fri, Oct 25
    75
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    75 Fri, Oct 25
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  • 1/2" External NPT<br>Heating Expansion<br>Tank (4.4 Gallon) Product Image
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    1/2" External NPT Heating Expansion Tank (4.4 Gallon) TK300-30 1/2" External NPT Heating Expansion Tank (4.4 Gallon)
    SKU: TK300-30
    Brand: Honeywell-Sparco
    (1)
    $42.45 each
    94
    Fri, Oct 25
    94
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    94 Fri, Oct 25
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  • Fill Control Valve Product Image
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    Fill Control Valve 109-15 Fill Control Valve
    SKU: 109-15
    Brand: Amtrol
    (8)
    $43.55 each
    $167.40 box of 4
    $41.85 each
    43
    Fri, Oct 25
    43
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    43 Fri, Oct 25
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  • RX-15 Radiant Extrol Expansion Tank (2 Gallon) Product Image
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    RX-15 Radiant Extrol Expansion Tank (2 Gallon) 140-705 RX-15 Radiant Extrol Expansion Tank (2 Gallon)
    SKU: 140-705
    Brand: Amtrol
    (6)
    $57.75 each
    $221.80 box of 4
    $55.45 each
    18
    Fri, Oct 25
    18
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    18 Fri, Oct 25
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  • RBFF, 1/2" Residential Boiler Fill Fitting Product Image
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    RBFF, 1/2" Residential Boiler Fill Fitting 0386466 RBFF, 1/2" Residential Boiler Fill Fitting
    SKU: 0386466
    Brand: Watts
    (4)
    $66.99 each
    $320.45 box of 5
    $64.09 each
    71
    Fri, Oct 25
    71
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    71 Fri, Oct 25
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  • Flexconsole - 3/4" x 1/2" NPT - Stainless Steel (White) Product Image
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    Flexconsole - 3/4" x 1/2" NPT - Stainless Steel (White) 97976-FLAMCO Flexconsole - 3/4" x 1/2" NPT - Stainless Steel (White)
    SKU: 97976-FLAMCO
    Brand: Flamco
    $66.95 each
    7
    Fri, Oct 25
    7
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    7 Fri, Oct 25
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  • ETX-60, Non-Potable Water Expansion Tank<br>(6.0 Gallon) Product Image
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    ETX-60, Non-Potable Water Expansion Tank (6.0 Gallon) 0066607 ETX-60, Non-Potable Water Expansion Tank (6.0 Gallon)
    SKU: 0066607
    Brand: Watts
    (5)
    $59.99 each
    $288.45 box of 5
    $57.69 each
    22
    Fri, Oct 25
    22
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    22 Fri, Oct 25
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  • Model 110 Fill-Trol<br>Tank Only (4.4 Gallon) Product Image
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    Model 110 Fill-Trol Tank Only (4.4 Gallon) 110-002 Model 110 Fill-Trol Tank Only (4.4 Gallon)
    SKU: 110-002
    Brand: Amtrol
    (10)
    $70.55 each
    $271.00 box of 4
    $67.75 each
    16
    Fri, Oct 25
    16
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    16 Fri, Oct 25
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Resources

Videos

Articles

  • An expansion tank is designed to relieve pressure in both a potable water and closed heating system. An expansion tank ensures a constant pressure is maintained within the pipes so they do not get damaged from excess pressure.

    An expansion tank has two parts which are divided by a rubber diaphragm. The top portion of the tank is connected to the hot water system and is filled with water. The bottom portion is filled with air set at approximately 12 psi. As the hot water system is turned on or off, pressure increases. As pressure increases, the diaphragm in the expansion tank is pushed down. This compresses the air in the tank, creating more space for excess water to enter. This relieves excess pressure in the system and prevents pipes in the system from being damaged.

    In the event that the diaphragm fails, the tank will completely fill with water. If this occurs, the tank must be replaced immediately. To check if the expansion tank is working properly, simply place your hand on the tank and feel its temperature. The top portion of the tank should feel warm to the touch, and the bottom portion of the tank should be room temperature. If the entire tank is warm, it is likely that the tank has completely filled with hot water.

    Expansion tanks have capacities ranging from 2 gallons to several hundred gallons. To determine the size needed for your system, use the Expansion Tank Sizing Calculator.

    We offer a wide selection of Amtrol, Watts, Cash Acme, and Bell & Gossett expansion tanks to suit all of your plumbing and heating needs.
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