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Expansion Tanks
Expansion Tanks
Lead Content Warning
Do not use this item for any installation or repair of potable water applications. This product does not comply with the "Safe Drinking Water Act," which requires that products meet low-lead standards in order to be used in systems providing water for human consumption (drinking or cooking). This item is for non-potable (non-human consumption) water applications only.
Lead Content Warning
This product does not comply with the Safe Drinking Water Act, which requires that products used in any system providing water for human consumption (drinking or cooking) to meet low-lead standards. Please check the box below to confirm you are aware that this item is for non-potable water applications only.
You must agree to this statement in order to purchase this product.
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Add to ListAdd to ListModel 110 Fill-Trol w/ Valve (4.4 Gallon) 110-1 Model 110 Fill-Trol w/ Valve (4.4 Gallon)SKU: 110-1Brand: Amtrol(46)Add to List -
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Add to ListAdd to ListSX-30V Extrol Expansion Tank (14 Gallon) 118-27 SX-30V Extrol Expansion Tank (14 Gallon)SKU: 118-27Brand: Amtrol(10)Add to List -
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Add to ListAdd to ListETX-30, Non-Potable Water Expansion Tank (4.5 Gallon) 0066606 ETX-30, Non-Potable Water Expansion Tank (4.5 Gallon)SKU: 0066606Brand: Watts(14)Add to List -
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Add to ListAdd to List#90 Extrol Expansion Tank (14 Gallon) 112-1 #90 Extrol Expansion Tank (14 Gallon)SKU: 112-1Brand: Amtrol(11)Add to List -
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Add to ListAdd to List1/2" External NPT Heating Expansion Tank (4.4 Gallon) TK300-30 1/2" External NPT Heating Expansion Tank (4.4 Gallon)SKU: TK300-30Brand: Honeywell(4)Add to List -
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Add to ListAdd to ListETX-60, Non-Potable Water Expansion Tank (6.0 Gallon) 0066607 ETX-60, Non-Potable Water Expansion Tank (6.0 Gallon)SKU: 0066607Brand: Watts(6)Add to List -
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Add to ListAdd to ListRX-15 Radiant Extrol Expansion Tank (2 Gallon) 140-705 RX-15 Radiant Extrol Expansion Tank (2 Gallon)SKU: 140-705Brand: Amtrol(7)Add to List -
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Add to ListAdd to ListModel 110 Fill-Trol Tank Only (4.4 Gallon) 110-002 Model 110 Fill-Trol Tank Only (4.4 Gallon)SKU: 110-002Brand: Amtrol(11)Add to List -
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Add to ListAdd to ListHFT-30, Hydronic Heating Expansion Tank (4.4 Gallon) 1BN327 HFT-30, Hydronic Heating Expansion Tank (4.4 Gallon)SKU: 1BN327Brand: Bell & Gossett(1)Add to List -
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Add to ListAdd to ListSX-160V Extrol Expansion Tank (86 Gallon) 118-155 SX-160V Extrol Expansion Tank (86 Gallon)SKU: 118-155Brand: Amtrol(2)10Wed, Nov 11 – Fri, Nov 13Add to List -
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Add to ListAdd to ListHFT-15, Hydronic Heating Expansion Tank (2 Gallon) 1BN326 HFT-15, Hydronic Heating Expansion Tank (2 Gallon)SKU: 1BN326Brand: Bell & Gossett(3)Add to List -
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Add to ListAdd to ListFlat Rectangular Hydronic Wall Hung Expansion Tank w/ Union Check (4.8 Gal.) ZFT18R Flat Rectangular Hydronic Wall Hung Expansion Tank w/ Union Check (4.8 Gal.)SKU: ZFT18RBrand: Zilmet(1)17Tue, Nov 10 – Wed, Nov 11Add to List -
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Add to ListAdd to ListFlat Rectangular Hydronic Wall Hung Expansion Tank w/ Union Check (2.1 Gal.) ZFT8R Flat Rectangular Hydronic Wall Hung Expansion Tank w/ Union Check (2.1 Gal.)SKU: ZFT8RBrand: Zilmet11Fri, Nov 6Add to List -
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Add to ListAdd to ListHFT-60, Hydronic Heating Expansion Tank (7.6 Gallon) 1BN328 HFT-60, Hydronic Heating Expansion Tank (7.6 Gallon)SKU: 1BN328Brand: Bell & GossettAdd to List -
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Add to ListAdd to ListFlat Round Hydronic Wall Hung Expansion Tank w/ Union Check (2.1 Gallon) ZFT8C Flat Round Hydronic Wall Hung Expansion Tank w/ Union Check (2.1 Gallon)SKU: ZFT8CBrand: ZilmetAdd to List -
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Add to ListAdd to List1/2" External NPT Heating Expansion Tank (7.6 Gallon) TK300-60 1/2" External NPT Heating Expansion Tank (7.6 Gallon)SKU: TK300-60Brand: HoneywellAdd to List -
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Add to ListAdd to List7Fri, Nov 6Add to List
FAQs, Manuals & Videos
Resources
Articles
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More About Expansion Tanks
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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