Well Pressure Tanks & Parts

Well pressure tanks and parts are the components that maintain steady water pressure in residential and light commercial well water systems, reduce pump cycling, and protect the pump from short cycling damage. A well pressure tank stores pressurized water between pump cycles so the pump doesn't fire every time a fixture opens. The category at SupplyHouse spans pre-pressurized diaphragm tanks from Amtrol Well-X-Trol and Red Lion Pumps, plus the accessories required to complete a pressure tank installation: pressure switches from Telemecanique (Square D), tank tee packages from Boshart and Bluefin, Amtrol Wel-Flo tanks, and Durabase stands. Brands carried include Amtrol, Red Lion Pumps, Telemecanique (Square D), Boshart, Bluefin, and Zilmet, covering the full range of residential well system installation and service needs.

KEY SUBCATEGORIES / PRODUCT TYPES

Amtrol Well-X-Trol Diaphragm Well Tanks

Amtrol Well-X-Trol tanks are pre-pressurized diaphragm well tanks featuring high-strength steel construction with Tuf-Kote HG Blue indoor/outdoor coating, a heavy-duty butyl diaphragm, an antimicrobial polypropylene liner, a stainless steel system connection, and a welded air valve permanently attached to prevent air loss. All Well-X-Trol models carry a 150 PSIG maximum working pressure, a 38 PSIG factory precharge, a 200°F maximum operating temperature, and a maximum relief valve setting of 125 PSIG. All parts including the polypropylene liner, butyl diaphragm, and stainless steel system connection are listed to NSF International Standard 61. Well-X-Trol tanks are available in stand and Durabase stand configurations. Key stocked models include the WX-202 (20 gallons, 32" height, 15" diameter, 1" NPTF system connection), the WX-203 (32 gallons, 47" height, 15" diameter, 1" NPTF system connection, 7-year limited warranty), the WX-250 (44 gallons, 36" height, 22" diameter, 1-1/4" NPTF system connection), the WX-302 (86 gallons, 47" height, 26" diameter, stainless steel system connection), and the WX-350 (119 gallons, 62" height, 26" diameter, 1-1/4" NPTF system connection). The WX-203 carries a 7-year limited warranty.

Amtrol Wel-Flo Diaphragm Well Tanks

Amtrol Wel-Flo tanks are pre-pressurized diaphragm well water system tanks sharing Amtrol's unique diaphragm design as an alternative to bladder-style and import tanks. The WF-32 (SKU WF100) carries 32 gallons, stands 46.5" tall, has a 15-3/8" diameter, uses a 1" system connection, carries a 100 psi maximum working pressure, and comes with a 5-year warranty. Wel-Flo tanks feature durable steel construction with an appliance-like finish, a polypropylene liner, and a butyl/EPDM blend diaphragm that permanently separates water and air and won't crease or trap debris like bladder designs. Wel-Flo tanks serve as the value alternative within the Amtrol well tank lineup.

Red Lion Pre-Charged Well Pressure Tanks

Red Lion pre-charged well pressure tanks are constructed with heavy-duty 20-gauge steel, a 304 stainless steel water connection with patented leak-safe technology, and are built to maintain water pressure in residential water pump systems when the pump isn't running. The Red Lion lineup at SupplyHouse includes vertical, horizontal, and inline configurations covering sizes from 4.5 gallons through 81 gallons. Specific models include the RL4A (4.5 gal, 3/4" MNPT straight connect, inline, SKU 604653), the RL6AH (6 gal, 3/4" MNPT straight connect, horizontal), the RL14AH (14 gal, 3/4" MNPT straight connect, horizontal), the RL14A (14 gal, 1" FNPT elbow connect, vertical), the RL20A (20 gal, 1" FNPT elbow connect, vertical), and the RL81A (81 gal, 1-1/4" FNPT elbow connect, vertical). Red Lion pre-charged well pressure tanks are designed for residential water pump system applications.

Tank Tee Packages

Tank tee packages are pre-assembled hardware kits that connect the pressure tank to the system piping and include a tee body, pressure switch, pressure gauge, and in some configurations a relief valve and union connection. Boshart stainless steel union tank tee packages include the TFP-ST25S2U (1" x 4-1/2" MPT stainless steel union, 30-50 PSI, SKU TFP-ST25S2U) and TFP-ST25S2UJ24 (1" x 4-1/2" MPT stainless steel union, 40-60 PSI, SKU TFP-ST25S2UJ24). Bluefin solid brass tank tee packages include the 1" x 10" center-to-end 30-50 PSI (SKU TTPS100-10) and 40-60 PSI (SKU TTPS100-10-B), and the 1-1/4" x 13" center-to-end 30-50 PSI (SKU TTPS125-13) and 40-60 PSI (SKU TTPS125-13-B). Bluefin also offers union brass tank tee packages in 1" (SKU TTPU100-10) and 1-1/4" x 13" 30-50 PSI (SKU TTPU125-13). The Zilmet ZTT-1 (SKU ZTT-1) is a 1" FNPT swivel union connection short well tank tee.

Pressure Switches

Telemecanique (Square D) 9013FSG series water pump pressure switches are diaphragm-actuated switches rated for all pump types including jet, submersible, and reciprocating, and are UL Listed, CSA certified, and certified to ANSI/NSF Standard 61. The 9013FSG series features drift-proof cut-in and cut-out settings, DPST double-break form YY contacts, a 1/4" NPSF fluid connection port, and a NEMA 1 enclosure in polypropylene. Available settings include 20/40 PSI (SKU 9013FSG2J20), 30/50 PSI (SKU 9013FSG2J21), and 40/60 PSI (SKU 9013FSG2J24). Manual switch with low pressure cut-off variants are also stocked: 20/40 PSI with manual/low cut-off (SKU 9013FSG2J20M4), 30/50 PSI with manual/low cut-off (SKU 9013FSG2J21M4), and 40/60 PSI with manual/low cut-off (SKU 9013FSG2J24M4). All FSG series switches carry a 10A @ 575V AC contact rating and are rated for 1-1/2 HP at 120V single phase, 2 HP at 240V single phase, and 3 HP at 240V three phase.

BUYING GUIDE / HOW TO CHOOSE

Selecting the right well pressure tank starts with sizing based on pump flow rate and pressure switch setting. A tank that's too small cycles the pump too frequently, shortening pump life. Amtrol's ESP sizing framework recommends approximately one minute of pump run time (ESP I) for pumps up to 3/4 HP and approximately two minutes of run time (ESP II) for pumps over 3/4 HP. For a 10 GPM pump on a 40/60 PSI switch, Amtrol's sizing table points toward the WX-250 (44 gallons) or larger. Confirming tank selection against Amtrol's current sizing documentation for the specific pump and pressure switch is required before specifying.

Tank brand and construction are the second filter. Amtrol Well-X-Trol tanks carry 150 PSIG maximum working pressure, an antimicrobial polypropylene liner, and a heavy-duty butyl diaphragm that conforms exactly to the shell without stretching, creasing, or forming bubbles or corners that could trap sediment. Red Lion pre-charged tanks are built with 20-gauge steel and a 304 stainless steel connection with patented leak-safe technology. Amtrol Wel-Flo tanks carry 100 psi maximum working pressure with a butyl/EPDM blend diaphragm and polypropylene liner.

Physical dimensions determine whether the tank fits the installation space. The WX-202 and WX-203 share a 15" diameter footprint at 32" and 47" heights respectively. The WX-250 and WX-302 use a 22" and 26" diameter footprint. Confirming ceiling height and floor space against the tank's published dimensions before ordering prevents a delivery-day mismatch.

Pressure switch selection must match the system's cut-in/cut-out pressure setting and tank precharge. The tank precharge should be set 2 PSIG below the pump cut-in pressure. For a 30/50 PSI switch, set the precharge to 28 PSIG. For a 40/60 PSI switch, set the precharge to 38 PSIG, which matches the factory precharge on all Amtrol well tanks. Tank tee packages combining a tee body, switch, gauge, and union connection simplify the installation and make future service faster.

FAQs

What is a well pressure tank and how does it work?

A well pressure tank is a pre-pressurized vessel installed in a residential or light commercial well water system that stores pressurized water between pump cycles to maintain steady system pressure and reduce how often the pump fires. Diaphragm-style well pressure tanks, including Amtrol Well-X-Trol and Wel-Flo models, use a butyl diaphragm to permanently separate the pressurized air charge from the water. When the pump runs, water enters the tank and compresses the air charge. When a fixture opens, the compressed air pushes water out until the system pressure drops to the pump cut-in point and the pump restarts. Well pressure tanks are available in sizes from under 5 gallons to 119 gallons and are paired with a pressure switch set to the system's desired cut-in/cut-out pressure range.

What is the difference between Amtrol Well-X-Trol and Amtrol Wel-Flo tanks?

The key differences between Amtrol Well-X-Trol and Amtrol Wel-Flo tanks are maximum working pressure, liner material, and diaphragm construction. Well-X-Trol tanks carry a 150 PSIG maximum working pressure, an antimicrobial polypropylene liner listed to NSF International Standard 61, and a heavy-duty butyl diaphragm described by Amtrol as the thickest in the industry, with seamless construction that conforms exactly to the shell configuration. Wel-Flo tanks carry a 100 psi maximum working pressure, a polypropylene liner, and a butyl/EPDM blend diaphragm. Well-X-Trol tanks also carry a 7-year limited warranty on the WX-203, while Wel-Flo tanks carry a 5-year warranty. Both use Amtrol's diaphragm design that won't crease or trap debris as bladder-style tanks can.

What pressure switch settings are available for well systems, and which Square D models cover each setting?

Telemecanique (Square D) 9013FSG series pressure switches at SupplyHouse cover 20/40 PSI (SKU 9013FSG2J20), 30/50 PSI (SKU 9013FSG2J21), and 40/60 PSI (SKU 9013FSG2J24) in standard DPST configurations. Manual switch with low pressure cut-off variants are available at the same three settings: 20/40 PSI (SKU 9013FSG2J20M4), 30/50 PSI (SKU 9013FSG2J21M4), and 40/60 PSI (SKU 9013FSG2J24M4). All 9013FSG series switches carry a 10A rating, NEMA 1 enclosure, UL 508 listing, CSA certification, and ANSI/NSF Standard 61 certification. The manual switch variant includes an Auto/Off/Start lever that allows manually starting the pump if the low pressure cut-off trips.

How should well pressure tank precharge be set, and how does it relate to the pressure switch setting?

Well pressure tank precharge should be set to 2 PSIG below the pump cut-in pressure for the system's pressure switch. For a 30/50 PSI switch with a 30 PSI cut-in, the precharge should be set to 28 PSIG. For a 40/60 PSI switch with a 40 PSI cut-in, the precharge should be set to 38 PSIG, which matches the factory precharge on all Amtrol Well-X-Trol and Wel-Flo tanks. To check or adjust the precharge, the tank must be fully drained of water before measuring the air pressure at the valve stem. If water comes out of the valve stem when the tank is drained, the diaphragm may be compromised and the tank may require replacement.

What should a complete well pressure tank installation include?

A complete well pressure tank installation for a residential well system includes the pressure tank itself, a pressure switch matched to the desired cut-in/cut-out setting, a tank tee or manifold connecting the tank to the system piping, a pressure gauge, and a pressure relief valve. Tank tee packages from Boshart and Bluefin combine these components into single assemblies matched to 30-50 or 40-60 PSI switch settings and available in 1" and 1-1/4" connection sizes, in solid brass and stainless steel construction with solid and union connection options. A union tee makes future service and tank replacement faster by allowing the tank to be disconnected without cutting pipe.