Amtrol expansion tank size?

Steve_46

I'm not sure of the gallons of water given the volume of the
cast Iron Radiators, the 20 feet of 2" pipe, approx 16 feet of 1-1/4, approx 30 feet of 1". Then there must be about 50
feet of 3/4 all galvi pipe. Temp range is set to run between 160 and 180. This is an old house that is about 12
feet from basement ceiling to second floor floor. I hope this helps. Are you saying that it is possible that it may
need an expansion tank that large?
Thanks,
Steve

Steve_46

Amtrol expansion tank size?

I have an old two story house with 10 cast Iron radiators.
They are mostly approx. 4 inches thick, 28 inches high, and
about 30 inches wide. They have about 8 loops or sections
each. This was at one time an old gravity system and was
changed when the boiler was changed about 8 years ago. There
are 2 inch, 1-1/2 and inch galv. pipes in the basement. It is a two pipe system and has one ciculator now. I'm adding
an Amtrol 40 gal hot water heater on its own circulator and
putting just two of the bedroom on their own zone. The old
galv. expansion tank has to be removed because of leaks and
I want to put in an Amtrol expansion tank. The question is
what size should the expansion tank be? I was told that
because of the volume of water in the system I can not use
the regular expansion type. A friend of mine is recommending an Amtrol XS series 90 gallon tank. Do I need a 90 gallon expansion tank? Isn't that kind of big? I
know that the water will expand when heated but is it really
that much?
Any help will be greatly appreciated.
Steve

Terry

sizing

Need some info to size properly.
1. System Capacity (Gallons)
2. Min & Max Temp
3. Min & Max PRessure.

OR....
use a tank that is 50% capactiy of your existing ACET Tank.

hope this helps.

EIN

Glenn Harrison_2

Here's a couple of links for you.

My main supplier uses Flexcon brand expansion tanks, but in all honesty they are all about the same.

The first link is a quick sizing chart, based on the BTU input of your boiler, and what kind of emitters you have, in your case, cast iron radiators. This chart is also based on a standard operating pressure of 12 psi.

The second link is a cross reference chart to go from Flexcon to Amtrol.

The third link is a spec sheet on the actual size and water capacity of each tank. For example that SX90 you were told about holds 44 gallons of water.

Flexcon Sizing Sheet

Flexcon Cross Reference

Flexcon Specification Sheet

Steve_46

Thank you

Thank you both for taking the time to help, it is greatly appreciated. The links have given me a helpful and complete
resource to make an informed choice.
Thanks again,
Steve

greg_28

Err to the larger, there is no downside. Too small may spill through the pressure relief and make an annoying drip at least.