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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
    (254)
    $33.49 each
    2,814
    Thu, Jan 30
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    2,814 Thu, Jan 30
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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
    (66)
    $29.29 each
    936
    Thu, Jan 30
    936
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    936 Thu, Jan 30
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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
    (34)
    $65.85 each
    650
    Thu, Jan 30
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    650 Thu, Jan 30
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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-U QuickStrap Expansion Tank Mounting Bracket (2.5 Gal. Capacity)
    SKU: QS-U
    Brand: Holdrite
    $14.99 each
    417
    Thu, Jan 30
    417
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    417 Thu, Jan 30
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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
    (10)
    $22.29 each
    307
    Thu, Jan 30
    807
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    307 Thu, Jan 30
    500 Fri, Jan 31 – Mon, Feb 3
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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
    (49)
    $40.95 each
    178
    Thu, Jan 30
    178
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    178 Thu, Jan 30
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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
    (9)
    $22.95 each
    85
    Thu, Jan 30
    85
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    85 Thu, Jan 30
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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
    (27)
    $30.95 each
    Tue, Feb 4 – Thu, Feb 6
    Arrives
    Tue, Feb 4 – Thu, Feb 6
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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
    (42)
    $75.99 each
    154
    Thu, Jan 30
    154
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    154 Thu, Jan 30
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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
    (10)
    $129.99 each
    177
    Thu, Jan 30
    177
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    177 Thu, Jan 30
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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
    124
    Thu, Jan 30
    124
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    124 Thu, Jan 30
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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
    (18)
    $69.95 each
    81
    Thu, Jan 30
    81
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    81 Thu, Jan 30
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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
    (11)
    $114.95 each
    142
    Thu, Jan 30
    142
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    142 Thu, Jan 30
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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
    (13)
    $31.89 each
    73
    Thu, Jan 30
    73
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    73 Thu, Jan 30
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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
    (11)
    $164.95 each
    94
    Thu, Jan 30
    94
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    94 Thu, Jan 30
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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
    46
    Thu, Jan 30
    46
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    46 Thu, Jan 30
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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
    (3)
    $42.45 each
    65
    Thu, Jan 30
    65
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    65 Thu, Jan 30
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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
    27
    Thu, Jan 30
    27
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    27 Thu, Jan 30
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  • 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain - FIP x FIP (600 WOG) Product Image
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    1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain - FIP x FIP (600 WOG) H-44672 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain - FIP x FIP (600 WOG)
    SKU: H-44672
    Brand: Webstone
    $22.99 each
    70
    Thu, Jan 30
    379
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    70 Thu, Jan 30
    309 Fri, Jan 31 – Mon, Feb 3
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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
    44
    Thu, Jan 30
    44
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    44 Thu, Jan 30
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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
    (9)
    $43.55 each
    49
    Thu, Jan 30
    49
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    49 Thu, Jan 30
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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
    35
    Thu, Jan 30
    35
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    35 Thu, Jan 30
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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)
    $55.99 each
    19
    Thu, Jan 30
    19
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    19 Thu, Jan 30
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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
    (11)
    $70.55 each
    31
    Thu, Jan 30
    31
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    31 Thu, Jan 30
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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, and Bell & Gossett expansion tanks to suit all of your plumbing and heating needs.

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