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


Brand: Amtrol

Mfr Part#: 141N43

Model: ST-12

UPC#: 642031395672

Availability: In Stock
Usually ships: within 1 business day
Qty Price
$54.95 / each
x4 $211.80 / box
(4 x $52.95)
Add to cart
  • Description
  • Literature
  • Reviews
  • FAQs

Amtrol ST-12 (Therm-X-Trol) is a water heater expansion tank, 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.


Amtrol ST-12 Advantages:

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;


Amtrol ST-12 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.

Therm-X-Trol ST-12 Thermal Expansion Tank (4.4 Gal Volume) has an average 5.0 out of 5 rating based on 2 user reviews.
This product came up to my expectations/
By Alex (from Twp. of Washington, NJ) on 11/28/2011
"The order was delivered extremely quickly 2 days after the order was placed. My plumber installed the tank in 5 minutes. The old tank was full of water. I was extremely satisfied !"
reliable product
By mary (from pa) on 8/23/2011
great quality. and they have the best price
Indicate an email address where you wish to receive the answer to your question.
Enter numbers shown above without spaces. This step helps us to prevent automatic submissions.
can it be mounted horizontalygs6bk
Read 1 answer
Amtrol allows only for vertical installation of this expansion tank.
Answered on 7/11/2012 by PexUniverse Customer Service

Estimate Delivery Date & Cost

Ship to Zip Code:
Qty (Optional):

The following was added to your shopping cart: X
Continue shoppingCartProceed to Checkout

Forgot Your Password?

Enter your e-mail address below.
You will receive an e-mail
with password reset instructions.