Expansion Tank Distance

Old 02-20-15, 04:20 PM
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Expansion Tank Distance

I am planning on relocating an expansion tank from its current very inaccessible location behind the boiler. The new tank is an Amtrol #60 (diaphram 7.6 gallon). It will be typically connected from the bottom of a Spirovent with a TEE to the cold water input. All of this in on the intake side of the system circulator. Pumping away applies.

My question: It there a minimum or maximum distance for the expansion tank location from the air eliminator or boiler. Based only on physical ease ideally the expansion tank would be about 4 feet away. I have never seen this and wonder if it is acceptable.
Old 02-20-15, 04:28 PM
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Ideally, you want a minimum pressure drop between the expansion tank and the circulator pump's suction. Minimize elbows, valves, fittings, etc. But 4ft sounds pretty good. My conventional expansion tank is located about 35+ ft (flow-wise) ahead of the pump suction (as was then recommended by B&G), and the system has worked fine for 65 years.
Old 02-20-15, 05:07 PM
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There is no real distance issue. It can be put anywhere. Just make sure that there is nothing between the boiler and the tank that when closed isolates the tank from the boiler.
You say on the cold water inlet. I assume the feed is going into the tee. Just make sure there's nothing like a flocheck or anything like that between the tank and the boiler.
The only reason I mention it is if you have a tankless and the boiler calls for hot water and not heat that flocheck will separate the tank from the boiler.
Good Luck,
Old 02-20-15, 06:47 PM
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I have never seen this
Must not have seen mine!

Easily four feet... maybe more. Works perfect.

Just make sure that you 'pump away' from the tank, where ever it's located and you'll be fine.

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