Amtrol ST-42V
Amtrol ST-42V
Amtrol ST-42V
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Amtrol ST-42V
Amtrol ST-42V

Amtrol Therm-X-Trol - 20 Gallon - Vertical Thermal Expansion Tank



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Only 3 In-Stock
Ships Thursday, Apr 22nd
Shipping to60601
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*We currently CANNOT ship this product to Canada or any destination outside of the United States
Amtrol Therm-X-Trol - 20 Gallon - Vertical Thermal Expansion Tank
Amtrol Therm-X-Trol - 20 Gallon - Vertical Thermal Expansion Tank
Model: ST-42V
How-To Articles


    In 1954, Amtrol invented the thermal expansion tank to control pressure build-up in closed, hot water systems. Today they are continuing to roll out efficient and reliable tanks to improve your system. The ST vertical thermal expansion tank is a perfect example of this. By accepting expanded water caused by thermal expansion, the ST is able to then return the water to the system when hot water is used. The ST also prevents pressure relief valve discharge, dripping faucets, and intermittent toilet fill. From the strong deep drawn steel domes with corrosion resistant liner to the welded air charge fitting, the ST is designed to prevent damaging pressure buildup and eliminate energy and water waste. The ST-42V is ideal for large residential and light commercial applications.
  • USA Made
  • All ST thermal expansion tanks are made in the USA at facilities certified for maintaining high-quality standards.
  • Heavy Duty Tank
  • From the deep drawn steel dome with rigid polypropylene liner to the welded air charge fitting, this thermal expansion tank is constructed from top to bottom for maximum strength and corrosion resistance.
  • Eliminates Wasted Energy
  • Expanded water caused by thermal expansion is collected by the ST tank which returns the water back to your system which preventing faucet drips, intermittent toilet fill, and pressure relief valve discharge.
  • Protection for Your System
  • ST thermal expansion tanks are designed to protect your water heater, fixtures, and appliances by preventing dangerous pressure build up.
  • Adaptable
  • Multiple tanks can be installed to accommodate large systems.


General Information
Product Line
Connection Type
Maximum Operating Temperature
200 F
Maximum Operating Pressure
150 PSI
Storage Volume
20 Gallons
Maximum Acceptance Volume
11.4 Gallons
Connection Size
3/4 Inch
Product Diameter
15 3/8 Inches
Product Height
31 5/8 Inches
Shipping Width
15 Inches
Shipping Height
32 Inches
Shipping Length
15 Inches
Country of Origin
United States
Warranty Information
Warranty Learn More
A warranty is a safeguard from defects in manufacturing and can vary in length and terms. To see the manufacturer's warranty statement, click on the Manuals tab. Learn More
1 Year


Amtrol ST-42V Reviews & Ratings

Recommended Accessories

Expert Recommended Accessories Selected by Bob, our Expert
Required Accessories 9
These accessories are required to properly setup/install this product.
Optional Accessories 10

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