Expansion Tanks

  • #30 Extrol Expansion Tank (4.4 Gallon)
    SKU: 102-1
    Brand: Amtrol
    (193)
    $35.95 each
    $137.80 box of 4
    $34.45 each
    1,495
    Wed, Oct 31
    1,495
    QtyArrives
    1,495 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • #15 Extrol Expansion Tank (2 Gallon)
    SKU: 101-1
    Brand: Amtrol
    (51)
    $29.95 each
    $115.00 box of 4
    $28.75 each
    503
    Wed, Oct 31
    503
    QtyArrives
    503 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • #60 Extrol Expansion Tank (7.6 Gallon)
    SKU: 103-1
    Brand: Amtrol
    (25)
    $61.65 each
    $235.80 box of 4
    $58.95 each
    349
    Wed, Oct 31
    349
    QtyArrives
    349 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • $16.85 each
    $161.50 box of 10
    $16.15 each
    323
    Wed, Oct 31
    823
    QtyArrives
    323 Wed, Oct 31
    500 Fri, Nov 2 – Mon, Nov 5
    Questions? Call 1-888-757-4774
  • 11" HydroClaw Expansion Tank Support Bracket
    SKU: HC11-A
    Brand: Storm King Enterprises
    (37)
    $40.95 each
    72
    Wed, Oct 31
    72
    QtyArrives
    72 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • $14.65 each
    $139.50 box of 10
    $13.95 each
    141
    Wed, Oct 31
    141
    QtyArrives
    141 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • $16.55 each
    $158.50 box of 10
    $15.85 each
    203
    Wed, Oct 31
    203
    QtyArrives
    203 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • $32.95 each
    $315.50 box of 10
    $31.55 each
    182
    Wed, Oct 31
    182
    QtyArrives
    182 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • 8" HydroClaw Expansion Tank Support Bracket
    SKU: HC8-B
    Brand: Storm King Enterprises
    (22)
    $30.95 each
    43
    Wed, Oct 31
    43
    QtyArrives
    43 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • Model 110 Fill-Trol w/ Valve (4.4 Gallon)
    SKU: 110-1
    Brand: Amtrol
    (30)
    $79.95 each
    $307.80 box of 4
    $76.95 each
    103
    Wed, Oct 31
    114
    QtyArrives
    103 Wed, Oct 31
    11 Thu, Nov 1
    Questions? Call 1-888-757-4774
  • SX-30V Extrol Expansion Tank (14 Gallon)
    SKU: 118-27
    Brand: Amtrol
    (5)
    $125.95 each
    $359.85 box of 3
    $119.95 each
    43
    Wed, Oct 31
    43
    QtyArrives
    43 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • Flexconsole - 1/2" x 1/2" NPT - Steel (Red)
    Contains Lead
    SKU: 97975
    Brand: Flamco
    (1)
    $22.95 each
    77
    Wed, Oct 31
    77
    QtyArrives
    77 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • 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
    60
    Wed, Oct 31
    60
    QtyArrives
    60 Wed, Oct 31
    Questions? Call 1-888-757-4774
  • RX-30 Radiant Extrol Expansion Tank (4.4 Gallon)
    SKU: 141-305
    Brand: Amtrol
    (9)
    $65.95 each
    $251.80 box of 4
    $62.95 each
    57
    Wed, Oct 31
    63
    QtyArrives
    57 Wed, Oct 31
    6 Thu, Nov 1
    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
    84
    Wed, Oct 31
    84
    QtyArrives
    84 Wed, Oct 31
    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
    37
    Wed, Oct 31
    45
    QtyArrives
    37 Wed, Oct 31
    8 Thu, Nov 1
    Questions? Call 1-888-757-4774
  • $65.95 each
    $314.75 box of 5
    $62.95 each
    33
    Wed, Oct 31
    39
    QtyArrives
    33 Wed, Oct 31
    6 Thu, Nov 1
    Questions? Call 1-888-757-4774
  • $31.15 each
    $298.50 box of 10
    $29.85 each
    100
    Wed, Oct 31
    100
    QtyArrives
    100 Wed, Oct 31
    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
    15
    Wed, Oct 31
    19
    QtyArrives
    15 Wed, Oct 31
    4 Thu, Nov 1
    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
    20
    Wed, Oct 31
    21
    QtyArrives
    20 Wed, Oct 31
    1 Thu, Nov 1
    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
    28
    Wed, Oct 31
    30
    QtyArrives
    28 Wed, Oct 31
    2 Thu, Nov 1
    Questions? Call 1-888-757-4774
  • Model 110 Fill-Trol Tank Only (4.4 Gallon)
    SKU: 110-002
    Brand: Amtrol
    (10)
    $65.95 each
    $251.80 box of 4
    $62.95 each
    14
    Wed, Oct 31
    18
    QtyArrives
    14 Wed, Oct 31
    4 Thu, Nov 1
    Questions? Call 1-888-757-4774
  • RBFF, 1/2" Residential Boiler Fill Fitting
    SKU: 0386466
    Brand: Watts
    (3)
    $53.95 each
    $259.75 box of 5
    $51.95 each
    37
    Wed, Oct 31
    37
    QtyArrives
    37 Wed, Oct 31
    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
    21
    Wed, Oct 31
    26
    QtyArrives
    21 Wed, Oct 31
    5 Thu, Nov 1
    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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