Expansion Tanks

  • #30 Extrol Expansion Tank (4.4 Gallon)
    SKU: 102-1
    Brand: Amtrol
    (219)
    $38.45 each
    $147.80 box of 4
    $36.95 each
    2,611
    Fri, May 3
    2,611
    QtyArrives
    2,611 Fri, May 3
    Questions? Call 1-888-757-4774
  • #15 Extrol Expansion Tank (2 Gallon)
    SKU: 101-1
    Brand: Amtrol
    (58)
    $31.95 each
    $122.60 box of 4
    $30.65 each
    795
    Fri, May 3
    795
    QtyArrives
    795 Fri, May 3
    Questions? Call 1-888-757-4774
  • #60 Extrol Expansion Tank (7.6 Gallon)
    SKU: 103-1
    Brand: Amtrol
    (28)
    $65.85 each
    $253.00 box of 4
    $63.25 each
    330
    Fri, May 3
    330
    QtyArrives
    330 Fri, May 3
    Questions? Call 1-888-757-4774
  • $19.95 each
    $191.50 box of 10
    $19.15 each
    130
    Fri, May 3
    630
    QtyArrives
    130 Fri, May 3
    500 Mon, May 6 – Tue, May 7
    Questions? Call 1-888-757-4774
  • 11" HydroClaw Expansion Tank Support Bracket
    SKU: HC11-A
    Brand: Storm King Enterprises
    (40)
    $40.95 each
    26
    Fri, May 3
    26
    QtyArrives
    26 Fri, May 3
    Questions? Call 1-888-757-4774
  • $14.85 each
    $142.50 box of 10
    $14.25 each
    102
    Fri, May 3
    102
    QtyArrives
    102 Fri, May 3
    Questions? Call 1-888-757-4774
  • $17.25 each
    $165.50 box of 10
    $16.55 each
    157
    Fri, May 3
    157
    QtyArrives
    157 Fri, May 3
    Questions? Call 1-888-757-4774
  • 8" HydroClaw Expansion Tank Support Bracket
    SKU: HC8-B
    Brand: Storm King Enterprises
    (24)
    $30.95 each
    Mon, Jun 3 – Mon, Jul 1
    Arrives
    Mon, Jun 3 – Mon, Jul 1
    Questions? Call 1-888-757-4774 or
  • Flexconsole - 1/2" x 1/2" NPT - Steel (Red)
    Contains Lead
    SKU: 97975
    Brand: Flamco
    (7)
    $22.95 each
    91
    Fri, May 3
    91
    QtyArrives
    91 Fri, May 3
    Questions? Call 1-888-757-4774
  • $39.55 each
    $379.50 box of 10
    $37.95 each
    101
    Fri, May 3
    101
    QtyArrives
    101 Fri, May 3
    Questions? Call 1-888-757-4774
  • Model 110 Fill-Trol w/ Valve (4.4 Gallon)
    SKU: 110-1
    Brand: Amtrol
    (34)
    $85.65 each
    $329.00 box of 4
    $82.25 each
    121
    Fri, May 3
    121
    QtyArrives
    121 Fri, May 3
    Questions? Call 1-888-757-4774
  • SX-30V Extrol Expansion Tank (14 Gallon)
    SKU: 118-27
    Brand: Amtrol
    (6)
    $135.95 each
    $391.65 box of 3
    $130.55 each
    110
    Fri, May 3
    110
    QtyArrives
    110 Fri, May 3
    Questions? Call 1-888-757-4774
  • Model 109 Fill-Trol w/ Valve (2 Gallon)
    SKU: 109-1
    Brand: Amtrol
    (15)
    $69.95 each
    $268.60 box of 4
    $67.15 each
    81
    Fri, May 3
    81
    QtyArrives
    81 Fri, May 3
    Questions? Call 1-888-757-4774
  • RX-30 Radiant Extrol Expansion Tank (4.4 Gallon)
    SKU: 141-305
    Brand: Amtrol
    (10)
    $70.45 each
    $270.60 box of 4
    $67.65 each
    99
    Fri, May 3
    99
    QtyArrives
    99 Fri, May 3
    Questions? Call 1-888-757-4774
  • #90 Extrol Expansion Tank (14 Gallon)
    SKU: 112-1
    Brand: Amtrol
    (10)
    $114.95 each
    $441.40 box of 4
    $110.35 each
    72
    Fri, May 3
    72
    QtyArrives
    72 Fri, May 3
    Questions? Call 1-888-757-4774
  • SX-40V Extrol Expansion Tank (20 Gallon)
    SKU: 118-78
    Brand: Amtrol
    (9)
    $164.95 each
    $475.05 box of 3
    $158.35 each
    79
    Fri, May 3
    79
    QtyArrives
    79 Fri, May 3
    Questions? Call 1-888-757-4774
  • SX-60V Extrol Expansion Tank (32 Gallon)
    SKU: 118-79
    Brand: Amtrol
    (1)
    $215.95 each
    $414.70 box of 2
    $207.35 each
    44
    Fri, May 3
    44
    QtyArrives
    44 Fri, May 3
    Questions? Call 1-888-757-4774
  • Fill Control Valve
    SKU: 109-15
    Brand: Amtrol
    (8)
    $43.55 each
    $167.40 box of 4
    $41.85 each
    45
    Fri, May 3
    45
    QtyArrives
    45 Fri, May 3
    Questions? Call 1-888-757-4774
  • RBFF, 1/2" Residential Boiler Fill Fitting
    SKU: 0386466
    Brand: Watts
    (4)
    $64.75 each
    $309.75 box of 5
    $61.95 each
    18
    Fri, May 3
    18
    QtyArrives
    18 Fri, May 3
    Questions? Call 1-888-757-4774
  • 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
    35
    Fri, May 3
    35
    QtyArrives
    35 Fri, May 3
    Questions? Call 1-888-757-4774
  • $37.35 each
    $358.50 box of 10
    $35.85 each
    46
    Fri, May 3
    46
    QtyArrives
    46 Fri, May 3
    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
    16
    Fri, May 3
    16
    QtyArrives
    16 Fri, May 3
    Questions? Call 1-888-757-4774
  • $66.95 each
    11
    Fri, May 3
    11
    QtyArrives
    11 Fri, May 3
    Questions? Call 1-888-757-4774
  • $78.95 each
    $379.75 box of 5
    $75.95 each
    42
    Fri, May 3
    42
    QtyArrives
    42 Fri, May 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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