Amtrol ST-5C-DD
Amtrol ST-5C-DD
Amtrol ST-5C-DD
Hover to zoom
1 Of 5
Amtrol ST-5C-DD
Amtrol ST-5C-DD

Amtrol Therm-X-Trol® - 2 Gallon - In-Line Thermal Expansion Tank - ASME Certified



Write a Review
Free Shipping
  Learn More About Free Freight
Ships in 1-2 Business Days
Shipping to60601
synchrony card logo
$200 / Month
Suggested monthly payments with 6 month financing.
Amtrol Therm-X-Trol® - 2 Gallon - In-Line Thermal Expansion Tank - ASME Certified
Amtrol Therm-X-Trol® - 2 Gallon - In-Line Thermal Expansion Tank - ASME Certified
Model: ST-5C-DD
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 Therm-X-Trol® in-line thermal expansion tank is a perfect example of this. By accepting expanded water caused by thermal expansion, this expansion tank is able to then return the water to the system when hot water is used. The Therm-X-Trol® 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 Therm-X-Trol® is designed to prevent damaging pressure buildup and eliminate energy and water waste. The ST-5C-DD is ideal for commercial applications.
  • USA Made, ASME Certified
  • All ST-C thermal expansion tanks are made in US facilities and meet ASME Section VIII, Division 1 standards.
  • Heavy Duty Tank
  • Amtrol's diaphragm design features an ASME approved steel shell for increased strength, while its reduced diameter and weight allow for easy handling and installation.
  • Eliminates Wasted Energy
  • Expanded water collected by the Therm-X-TrolŪ tank returns the water back to your system, preventing faucet drips, intermittent toilet fill, and pressure relief valve discharge.
  • Protection for Your System
  • Therm-X-TrolŪ thermal expansion tanks are designed to protect your water heater, fixtures, and appliances by preventing dangerous pressure build up.
  • Antimicrobial Protection
  • The Therm-X-TrolŪ tank features an antimicrobial inner lining that neutralizes bacteria in your water system on contact. This safe, silver-ion technology targets only active microorganisms.
  • Fresh Water Turbulator™
  • The Therm-X-Trol'sŪ Fresh Water Turbulator™ agitates the incoming water stream, creating a water-jet scrubbing action that prevents sediment buildup and extends the life of your tank.
  • Product Note
    This product must be shipped freight due to shipping restrictions on pre-charged expansion tanks.


specs product image PID-81417
General Information
Product Line
Flange Material
Stainless Steel
Connection Type
Maximum Operating Temperature
200 F
Maximum Operating Pressure
150 PSI
Storage Volume
2 Gallons
Maximum Acceptance Volume
0.9 Gallons
Connection Size
3/4 Inch
Product Diameter
8 Inches
Product Height
14 Inches
Shipping Height
14 19/48 Inches
Shipping Width
9 Inches
Shipping Length
9 5/48 Inches
Country of Origin
United States
ASME Certified
Warranty Information
Warranty Learn More
1 Year


Amtrol ST-5C-DD Reviews & Ratings

Recommended Accessories

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

How-To Articles

What Size Tankless Water Heater Do I Need
What Size Tankless Water Heater Do I Need
Size matters when it comes to your tankless water heater. In fact, it is the mo...
Signs You Need a New Water Heater
Signs You Need a New Water Heater
You’ve heard the stories. A 60-gallon hot water heater tank ruptures, flo...
An Intro to Indirect Water Heaters
An Intro to Indirect Water Heaters
Did you know? If you get your heat from a boiler, you have the opportunity to a...
eComfort How-To Library
eComfort How-To Library
Articles, Tips and Buying Guides from Our Experts


Media Gallery
Amtrol Therm-X-Trol® - 2 Gallon - In-Line Thermal Expansion Tank - ASME Certified
Amtrol ST-5C-DD
Reset View
Amtrol ST-5C-DD
Amtrol ST-5C-DD
Customer Review Images