Is this for potable water?

It is not made for potable water system. But in a regular installation some water from the tank can mix with a potable water. The tank has a polypropylene liner and butyl diaphragm, which may be in contact with water. You have to decide for yourself if you want to drink water from a polypropylene container.

Can this tank be install horizontally?

Amtrol instruction says: "Mount tank vertically in downward position only. Ensure the piping can support the entire weight of the tank when full of water". This makes sense to me.

Is this compatable with ethylene glycol? I want it for the glycol side of a heat exchanger on a solar water heater.

I don't know. It may be best to contact the Amtrol technical support to see if ethylene glycol is compatible with the bladder diaphragm chemistry in this unit.

what's the capacity in gallons?

It's a 12 liter tank, so it holds approximately 4.4 gallons.

Amtrol St 12 Thermal Expansion Tank | Desertcart Isle of Man

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Description

💧 Stay ahead of pressure spikes—protect your home and wallet with Amtrol ST-12!

TRUSTED QUALITY - Made in USA with a proven track record and 4.6-star rating from 300+ users
DURABILITY BOOST - Extends water heater and plumbing lifespan by preventing premature failures
PRESSURE GUARDIAN - Keeps system pressure below relief valve threshold to avoid leaks and damage
ENERGY WATER SAVER - Eliminates costly thermal expansion waste for smarter utility bills
EASY INSTALLATION MAINTENANCE - Designed for hassle-free mounting and simple pressure checks with visual indicator

The Amtrol ST-12 Thermal Expansion Tank is a 4.4-gallon solution engineered to manage thermal expansion in closed potable water systems. By absorbing excess pressure, it prevents relief valve discharge, conserves water and energy, and safeguards your water heater and plumbing from premature wear. Trusted by professionals and homeowners alike, this durable, easy-to-install tank ensures efficient, safe hot water delivery while reducing costly system failures.

Specifications

ASIN	B001BNPSFW
Best Sellers Rank	#428,499 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #1,029 in Water Heater Replacement Parts
Color	White
Customer Reviews	4.6 4.6 out of 5 stars (324)
Date First Available	June 25, 2008
Item Package Quantity	1
Item Weight	2.2 pounds
Item model number	ST-12
Manufacturer	AMTROL
National Stock Number	5430-01-626-6547
Part Number	ST-12
Power Source	Ac/dc
Product Dimensions	8 x 11 x 15 inches
Size	one-size

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Our prices include the product cost, international shipping, import duties, customs clearance, and local delivery charges. We handle all customs and import procedures, ensuring there are no hidden fees upon delivery. PRO members receive additional benefits including free shipping.

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