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Expansion Tanks

  • #30 Extrol Expansion Tank (4.4 Gallon) Product Image
    #30 Extrol Expansion Tank (4.4 Gallon)
    SKU: 102-1
    Brand: Amtrol
    (224)
    $35.99 each
    $138.36 box of 4
    $34.59 each
    970
    Tue, Sep 3
    970
    QtyArrives
    970 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • #15 Extrol Expansion Tank (2 Gallon) Product Image
    #15 Extrol Expansion Tank (2 Gallon)
    SKU: 101-1
    Brand: Amtrol
    (59)
    $30.79 each
    $119.96 box of 4
    $29.99 each
    165
    Tue, Sep 3
    165
    QtyArrives
    165 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • #60 Extrol Expansion Tank (7.6 Gallon) Product Image
    #60 Extrol Expansion Tank (7.6 Gallon)
    SKU: 103-1
    Brand: Amtrol
    (29)
    $65.85 each
    $253.00 box of 4
    $63.25 each
    145
    Tue, Sep 3
    145
    QtyArrives
    145 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain Product Image
    $22.29 each
    $213.90 box of 10
    $21.39 each
    247
    Tue, Sep 3
    747
    QtyArrives
    247 Tue, Sep 3
    500 Tue, Sep 3 – Wed, Sep 4
    Questions? Call 1-888-757-4774
  • 11" HydroClaw Expansion Tank Support Bracket Product Image
    11" HydroClaw Expansion Tank Support Bracket
    SKU: HC11-A
    Brand: Storm King Enterprises
    (42)
    $40.95 each
    91
    Tue, Sep 3
    91
    QtyArrives
    91 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • QuickStrap Expansion Tank Mounting Bracket <br>(2.5 Gal. Capacity) Product Image
    $14.99 each
    $143.90 box of 10
    $14.39 each
    204
    Tue, Sep 3
    204
    QtyArrives
    204 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • QuickStrap Expansion Tank Mounting Bracket<br>(5 Gal. Capacity) Product Image
    $16.99 each
    $162.90 box of 10
    $16.29 each
    223
    Tue, Sep 3
    223
    QtyArrives
    223 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • Flexconsole - 1/2" x 1/2" NPT - Steel (Red) Product Image
    $22.95 each
    109
    Tue, Sep 3
    109
    QtyArrives
    109 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • 8" HydroClaw Expansion Tank Support Bracket Product Image
    8" HydroClaw Expansion Tank Support Bracket
    SKU: HC8-B
    Brand: Storm King Enterprises
    (25)
    $30.95 each
    75
    Tue, Sep 3
    75
    QtyArrives
    75 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • Model 110 Fill-Trol<br>w/ Valve (4.4 Gallon) Product Image
    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
    71
    Tue, Sep 3
    71
    QtyArrives
    71 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • ETX-30, Non-Potable Water Expansion Tank<br>(4.5 Gallon) Product Image
    $37.99 each
    $364.90 box of 10
    $36.49 each
    154
    Tue, Sep 3
    154
    QtyArrives
    154 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • SX-30V Extrol Expansion Tank (14 Gallon) Product Image
    SX-30V Extrol Expansion Tank (14 Gallon)
    SKU: 118-27
    Brand: Amtrol
    (7)
    $129.99 each
    $374.97 box of 3
    $124.99 each
    28
    Tue, Sep 3
    28
    QtyArrives
    28 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • Model 109 Fill-Trol<br>w/ Valve (2 Gallon) Product Image
    Model 109 Fill-Trol w/ Valve (2 Gallon)
    SKU: 109-1
    Brand: Amtrol
    (16)
    $69.95 each
    $268.60 box of 4
    $67.15 each
    56
    Tue, Sep 3
    56
    QtyArrives
    56 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • RX-30 Radiant Extrol Expansion Tank<br>(4.4 Gallon) Product Image
    $62.99 each
    $239.96 box of 4
    $59.99 each
    64
    Tue, Sep 3
    64
    QtyArrives
    64 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • #90 Extrol Expansion Tank (14 Gallon) Product Image
    #90 Extrol Expansion Tank (14 Gallon)
    SKU: 112-1
    Brand: Amtrol
    (10)
    $114.95 each
    $441.40 box of 4
    $110.35 each
    61
    Tue, Sep 3
    61
    QtyArrives
    61 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • SX-40V Extrol Expansion Tank (20 Gallon) Product Image
    SX-40V Extrol Expansion Tank (20 Gallon)
    SKU: 118-78
    Brand: Amtrol
    (10)
    $164.95 each
    $475.05 box of 3
    $158.35 each
    43
    Tue, Sep 3
    43
    QtyArrives
    43 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • SX-60V Extrol Expansion Tank (32 Gallon) Product Image
    SX-60V Extrol Expansion Tank (32 Gallon)
    SKU: 118-79
    Brand: Amtrol
    (1)
    $205.99 each
    $391.98 box of 2
    $195.99 each
    17
    Tue, Sep 3
    17
    QtyArrives
    17 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • Fill Control Valve Product Image
    Fill Control Valve
    SKU: 109-15
    Brand: Amtrol
    (8)
    $43.55 each
    $167.40 box of 4
    $41.85 each
    28
    Tue, Sep 3
    28
    QtyArrives
    28 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • RBFF, 1/2" Residential Boiler Fill Fitting Product Image
    RBFF, 1/2" Residential Boiler Fill Fitting
    SKU: 0386466
    Brand: Watts
    (4)
    $66.99 each
    $320.45 box of 5
    $64.09 each
    85
    Tue, Sep 3
    85
    QtyArrives
    85 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • RX-15 Radiant Extrol Expansion Tank (2 Gallon) Product Image
    $57.75 each
    $221.80 box of 4
    $55.45 each
    27
    Tue, Sep 3
    27
    QtyArrives
    27 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • 1/2" External NPT<br>Heating Expansion<br>Tank (4.4 Gallon) Product Image
    1/2" External NPT Heating Expansion Tank (4.4 Gallon)
    SKU: TK300-30
    Brand: Honeywell-Sparco
    (1)
    $42.45 each
    46
    Tue, Sep 3
    46
    QtyArrives
    46 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • Flexconsole - 3/4" x 1/2" NPT - Stainless Steel (White) Product Image
    $66.95 each
    22
    Tue, Sep 3
    22
    QtyArrives
    22 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • ETX-15, Non-Potable Water Expansion Tank<br>(2.1 Gallon) Product Image
    $34.999 each
    $335.90 box of 10
    $33.59 each
    60
    Tue, Sep 3
    60
    QtyArrives
    60 Tue, Sep 3
    Questions? Call 1-888-757-4774
  • ETX-60, Non-Potable Water Expansion Tank<br>(6.0 Gallon) Product Image
    $59.99 each
    $288.45 box of 5
    $57.69 each
    52
    Tue, Sep 3
    52
    QtyArrives
    52 Tue, Sep 3
    Questions? Call 1-888-757-4774

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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