Expansion Tanks

  • #30 Extrol Expansion Tank (4.4 Gallon)
    SKU: 102-1
    Brand: Amtrol
    (204)
    $35.95 each
    $137.80 box of 4
    $34.45 each
    2,041
    Thu, Dec 27
    2,041
    QtyArrives
    2,041 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • #15 Extrol Expansion Tank (2 Gallon)
    SKU: 101-1
    Brand: Amtrol
    (55)
    $29.95 each
    $115.00 box of 4
    $28.75 each
    306
    Thu, Dec 27
    306
    QtyArrives
    306 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • #60 Extrol Expansion Tank (7.6 Gallon)
    SKU: 103-1
    Brand: Amtrol
    (26)
    $61.65 each
    $235.80 box of 4
    $58.95 each
    209
    Thu, Dec 27
    209
    QtyArrives
    209 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • $19.45 each
    $186.50 box of 10
    $18.65 each
    154
    Thu, Dec 27
    654
    QtyArrives
    154 Thu, Dec 27
    500 Fri, Dec 28 – Mon, Dec 31
    Questions? Call 1-888-757-4774
  • 11" HydroClaw Expansion Tank Support Bracket
    SKU: HC11-A
    Brand: Storm King Enterprises
    (37)
    $40.95 each
    131
    Thu, Dec 27
    131
    QtyArrives
    131 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • $14.85 each
    $142.50 box of 10
    $14.25 each
    128
    Thu, Dec 27
    128
    QtyArrives
    128 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • $16.75 each
    $159.50 box of 10
    $15.95 each
    70
    Thu, Dec 27
    70
    QtyArrives
    70 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • $39.55 each
    $379.50 box of 10
    $37.95 each
    65
    Thu, Dec 27
    65
    QtyArrives
    65 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • 8" HydroClaw Expansion Tank Support Bracket
    SKU: HC8-B
    Brand: Storm King Enterprises
    (23)
    $30.95 each
    82
    Thu, Dec 27
    82
    QtyArrives
    82 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • Model 110 Fill-Trol w/ Valve (4.4 Gallon)
    SKU: 110-1
    Brand: Amtrol
    (33)
    $79.95 each
    $307.80 box of 4
    $76.95 each
    43
    Thu, Dec 27
    43
    QtyArrives
    43 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • Flexconsole - 1/2" x 1/2" NPT - Steel (Red)
    Contains Lead
    SKU: 97975
    Brand: Flamco
    (4)
    $22.95 each
    116
    Thu, Dec 27
    116
    QtyArrives
    116 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • SX-30V Extrol Expansion Tank (14 Gallon)
    SKU: 118-27
    Brand: Amtrol
    (6)
    $125.95 each
    $359.85 box of 3
    $119.95 each
    Fri, Jan 18 – Fri, Jan 25
    Arrives
    Fri, Jan 18 – Fri, Jan 25
    Questions? Call 1-888-757-4774 or LiveChat Img Live Chat
  • Model 109 Fill-Trol w/ Valve (2 Gallon)
    SKU: 109-1
    Brand: Amtrol
    (14)
    $63.95 each
    $247.80 box of 4
    $61.95 each
    Fri, Jan 18 – Fri, Jan 25
    Arrives
    Fri, Jan 18 – Fri, Jan 25
    Questions? Call 1-888-757-4774 or LiveChat Img Live Chat
  • RX-30 Radiant Extrol Expansion Tank (4.4 Gallon)
    SKU: 141-305
    Brand: Amtrol
    (10)
    $65.95 each
    $251.80 box of 4
    $62.95 each
    35
    Thu, Dec 27
    35
    QtyArrives
    35 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • #90 Extrol Expansion Tank (14 Gallon)
    SKU: 112-1
    Brand: Amtrol
    (9)
    $105.95 each
    $399.80 box of 4
    $99.95 each
    5
    Thu, Dec 27
    5
    QtyArrives
    5 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • SX-40V Extrol Expansion Tank (20 Gallon)
    SKU: 118-78
    Brand: Amtrol
    (8)
    $149.95 each
    $431.85 box of 3
    $143.95 each
    60
    Thu, Dec 27
    60
    QtyArrives
    60 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • Fill Control Valve
    SKU: 109-15
    Brand: Amtrol
    (7)
    $39.95 each
    $153.40 box of 4
    $38.35 each
    Fri, Jan 18 – Fri, Jan 25
    Arrives
    Fri, Jan 18 – Fri, Jan 25
    Questions? Call 1-888-757-4774 or LiveChat Img Live Chat
  • $37.35 each
    $358.50 box of 10
    $35.85 each
    63
    Thu, Dec 27
    63
    QtyArrives
    63 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • SX-60V Extrol Expansion Tank (32 Gallon)
    SKU: 118-79
    Brand: Amtrol
    (1)
    $212.95 each
    $407.90 box of 2
    $203.95 each
    4
    Thu, Dec 27
    6
    QtyArrives
    4 Thu, Dec 27
    2 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • $78.95 each
    $379.75 box of 5
    $75.95 each
    20
    Thu, Dec 27
    32
    QtyArrives
    20 Thu, Dec 27
    12 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • RX-15 Radiant Extrol Expansion Tank (2 Gallon)
    SKU: 140-705
    Brand: Amtrol
    (5)
    $53.95 each
    $207.80 box of 4
    $51.95 each
    2
    Thu, Dec 27
    3
    QtyArrives
    2 Thu, Dec 27
    1 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • RBFF, 1/2" Residential Boiler Fill Fitting
    SKU: 0386466
    Brand: Watts
    (3)
    $64.75 each
    $309.75 box of 5
    $61.95 each
    11
    Thu, Dec 27
    11
    QtyArrives
    11 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • $66.95 each
    9
    Thu, Dec 27
    9
    QtyArrives
    9 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • 1/2" External NPT Heating Expansion Tank (4.4 Gallon)
    SKU: TK300-30
    Brand: Honeywell-Sparco
    (1)
    $42.45 each
    27
    Thu, Dec 27
    33
    QtyArrives
    27 Thu, Dec 27
    6 Fri, Dec 28
    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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