Wellmate Fiberglass Pressure Tanks
WellMate's tanks feature corrosion-proof composite construction that require little or no maintenance, plus their light weight makes them easier and less costly to install. All materials meet stringent U.S. Requirements for water components and are NSF and/or FDA listed materials. WellMate continues its tradition of excellence by offering features and benefits steel tanks cannot match.
These rustproof WellMate pressure tanks are made with blow molded, fiberglass wrapped, seamless construction. They won't rust, dent, or come apart at the seams because there are no seams, and a rugged base is included. Full five-year limited warranty.
These tank now features the quick connect that snaps securely into place and is retained by an H-clip.
How to Size a Pressure Tank
Not interested in doing all the math below? Enter your values here to calculate.
Since its inception in 1964, the pre-pressurized potable water tank has assumed various designs and has proven useful in a wide variety of open-system applications. Originally used in well installations, this technology gained widespread acceptance and was soon applied in a variety of applications requiring pressurized water storage. With this flexibility, however, can come confusion as to installation scenarios and related sizing. Below, we 'll take a look at proper use and related sizing techniques in such applications as pump cycle control, volume maintenance, and water treatment systems.
Common to the below examples is the fact that it is necessary to determine both the amount of tank storage needed and the pressures necessary to obtain that storage. Simply stated: All sizings use the same principle with different values. Referred to as Boyle's Law of Ideal Gases, this principle will be used to determine how much water is stored in tank at a given pressure. This multiplier will be referred to as the Acceptance Factor. Keep this equation in mind as a foundation to size any pre-pressurized tank:

Pump Systems
It is common knowledge in the water systems industry that cycling a pump motor rapidly will often lead to failure. To prevent this, most pump manufacturers normally recommend a minimum pump runtime of 2 minutes. In order to achieve the runtime, the pre-pressurized tank must store a given volume of water between pump cycles. Doing so requires the pump to run for a specific period to fill the tank. In general, larger pumps require longer intervals between start cycles. When sizing a pre-pressurized tank for the above purpose, the following information should be known: Pump horsepower, pump output in gallons per minute (GPM), and pressure switch setting in psi (cut-in & cut-out). The below procedure will guide you through a sizing scenario using a 1hp pump. The pump will be operating at 15 GPM with a pressure switch setting of 40psi cut-in and 60psi cut-out. The Acceptance Factors have already been calculated in the chart provided. The figures are based on a tank precharge (initial air charge) set 2psi below pump cut-in pressure.
According to the "Recommended Minimum Runtime" notation, a 1hp pump should operate for a period of at least 2 minutes between motor starts. In order to run a 15GPM pump for 2 minutes, 30 gallons of storage is necessary. The Acceptance Factor indicates that 27% of a given tank's volume will be usable water between 40 and 60psi. Dividing 30 by an acceptance factor of .27 results in a tank with a volume of 111 gallons.
WellMate Pressure Tanks |
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Model | Tank Size | Total Volume |
Drawdown @30/50 (PSI) |
Drawdown @40/60 (PSI) |
Connector | Ship Weight | Price | ||
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WM-6 | 16" X 32" | 20 gallons | 5.9 gallons | 5.1 gallons | 1" NPTM | 19 lbs. |
OUR PRICE
$315.00
*Shipping Included! |
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WM-9 | 16" X 44" | 30 gallons | 8.9 gallons | 7.7 gallons | 1" NPTM | 31 lbs. |
OUR PRICE
$485.00
*Shipping Included! |
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WM-10LP | 24" X 28" | 35 gallons | 10.7 gallons | gallons | 1" NPTM | 36 lbs. |
OUR PRICE
$820.00
*Shipping Included! |
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WM-12 | 16" X 57" | 40 gallons | 12.2 gallons | 10.5 gallons | 1" NPTM | 29 lbs. |
OUR PRICE
$550.00
*Shipping Included! |
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WM-14WB | 21" X 41" | 47 gallons | 14.1 gallons | 12.2 gallons | 1 1/4" NPTM | 48 lbs. |
OUR PRICE
$675.00
*Shipping Included! |
Out of stock |
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WM-20WB | 24" X 42" | 60 gallons | 18 gallons | 16.2 gallons | 1 1/4" NPTM | 55 lbs. |
OUR PRICE
$805.00
*Shipping Included! |
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WM-25WB | 24" X 55" | 87 gallons | 26 gallons | 22.5 gallons | 1 1/4" NPTM | 82 lbs. |
OUR PRICE
$1,073.45
*Shipping Included! |
Out of stock |
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WM-35WB | 25" X 75" | 120 gallons | 34.2 gallons | 29.6 gallons | 1 1/4" NPTM | 121 lbs. |
OUR PRICE
$1,230.00
*Shipping Included! |
Out of stock |
Wellmate Butyl Air Cell Replacement Kits |
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Model | Tank Size | Total Volume |
Drawdown @30/50 (PSI) |
Drawdown @40/60 (PSI) |
Connector | Ship Weight | Price | ||
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CH3133-2 for WM-6 | 16" X 32" | 20 gallons | 5.9 gallons | 5.1 gallons | 1" NPTM | 5 lbs. |
OUR PRICE
$159.00
*Shipping Included! |
Out of stock |
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CH3134-2 for WM-9 | 16" X 44" | 30 gallons | 8.9 gallons | 7.7 gallons | 1" NPTM | 5 lbs. |
OUR PRICE
$189.00
*Shipping Included! |
Out of stock |
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CH3135-2 for WM-12 | 16" X 57" | 40 gallons | 12.2 gallons | 10.5 gallons | 1" NPTM | 5 lbs. |
OUR PRICE
$219.99
*Shipping Included! |
Out of stock |
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CH4466 for WM-14WB | 21" X 41" | 47 gallons | 14.1 gallons | 12.2 gallons | 1 1/4" NPTM | 10 lbs. |
OUR PRICE
$250.00
*Shipping Included! |
Out of stock |
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CH4846 for WM-20WB | 24" X 42" | 60 gallons | 18 gallons | 16.2 gallons | 1 1/4" NPTM | 11 lbs. |
OUR PRICE
$260.00
*Shipping Included! |
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CH4467 for WM-25 | 24" X 55" | 87 gallons | 26 gallons | 22.5 gallons | 1 1/4" NPTM | 12 lbs. |
OUR PRICE
$359.00
*Shipping Included! |
Out of stock |
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CH4468 for WM-35WB | 25" X 75" | 120 gallons | 34.2 gallons | 29.6 gallons | 1 1/4" NPTM | 22 lbs. |
OUR PRICE
$387.00
*Shipping Included! |
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Female Tank Tee Installation Packages

1" Female Tank Tee / 1" Incoming Water Line |
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Fits: Wellmate WM-6, WM-9, WM-12 Flexcon H2PL22, H2PL35, FL7, FL12 Amtrol WX-202-H, WX-200PS | ||||||||
Model | Price | |||||||
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SS-T1-F |
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MSRP $199.00 OUR PRICE $170.00*Shipping Included! |
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NL-BRASS-T1-F |
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MSRP $159.00 OUR PRICE $125.00*Shipping Included! |
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1.25" Female Tank Tee / 1" Incoming Water Line |
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Fits: Wellmate WM-14, WM-20, WM-25, WM-35 Flexcon H2PL38SQ, H2PL50, H2PL65, H2PL82, H2PL90, H2PL120 | ||||||||
Model | Price | |||||||
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SS-T2-F |
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MSRP $209.00 OUR PRICE $170.00*Shipping Included! |
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NL-BRASS-T2-F |
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MSRP $179.00 OUR PRICE $135.00*Shipping Included! |
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1.25" Female Tank Tee / 1.25" Incoming Water Line |
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Fits: Wellmate WM-14, WM-20, WM-25, WM-35 Flexcon H2PL38SQ, H2PL50, H2PL65, H2PL82, H2PL90, H2PL120 | ||||||||
Model | Price | |||||||
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SS-T2-1.25-F |
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MSRP $249.00 OUR PRICE $210.00*Shipping Included! |
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NL-BRASS-T2-1.25-F |
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MSRP $199.00 OUR PRICE $170.00*Shipping Included! |
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