Amtrol 141N43 Therm-X-Trol ST-12 Thermal Expansion Tank (4.4 Gal Volume)

Amtrol 141N43 Therm-X-Trol ST-12 Thermal Expansion Tank (4.4 Gal Volume)

The 141N43 from Amtrol is a Therm-X-Trol ST-12 Thermal Expansion Tank (4.4 gal volume). It's designed for use in domestic hot water heating systems to eliminate the potential hazards of water expansion. Water heater expansion tank is commonly installed in a domestic hot water system that contains a backflow preventer, a check valve or a pressure reducing valve.


  • Eliminates the waste of energy and water, thus saving money;
  • Protects the water heater and plumbing fixtures from premauture failure;
  • Reduces potential safety hazards associated with thermal expansion;
  • Prevents a dangerous pressure build-up in the system;
  • Prevents the relief valve from going off;
  • Therm-X-Trol brand is the #1 choice of Professional Installers;

Technical Specifications:

  • Factory pre-charged 40 psig;
  • System connection: 3/4" male threaded;
  • Stainless steel system connection;
  • Max. operating temperature: 200F;
  • Max. operating pressure: 150 psi;
  • Expansion tank volume: 4.4 gallons;
  • Max. acceptance factor: 0.73;
  • Height: 15";
  • Diameter: 11";
  • Shipping weight: 9 lbs;

Standards & Approvals:

  • NSF/ANSI 61®, IAPMO, SBCCI & City of Los Angeles listings.

Amtrol ST-12 Applications:

  • Residentail water heaters, laundromats, dormitories, office/apartment buildings, restaurants, etc.


  • 5-year manufacturer's warranty.
Product Specs
Application Plumbing
Capacity (Gallons): 4.4
Diameter (Inches): 11"
Height (Inches): 15.5
Material1 Steel
Max Accept. Factor: 0.73
Max Pressure (PSI): 150
Size1 3/4"
Tank Volume: 4.4 Gallons
Temperature Range (F): 200°F MAX
Warranty: 5-Year Limited Warranty
Weight (lbs): 9 lbs

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  • Amtrol 141N43 Therm-X-Trol ST-12 Thermal Expansion Tank (4.4 Gal Volume) QR Code
  • Model: 141N43
  • MPN: 141N43
  • Availability: 27
  • $ 80.95


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Tags: Expansion Tanks, Heating Supply, Plumbing Supply, PEX, Pipe Fittings, Residential Plumbing