Expansion tank and feed valve location question

Michael Welch

The directions for spirovent just state that it needs to be installed in a horizontal run there is no specified length. http://www.spirotherm.com/docs/installation/JrIOM-A.pdf

D107

Installer suggests expansion tank in a tee BEFORE the air

scoop to avoid hanging the full tank off of a 1/2" fitting if they have to ell and nipple it out past the boiler. Couldn't they use a clevis hanger to support from ceiling? I ask because the wall wisdom generally seems to be to place purge valve, air separator, expansion tank and feed pipe all coming together at the same point--the PONPC.

(page 48 Pumping Away by Dan Holohan.)(The PONPC) "...the only place in the system where the pump can't affect the feed valve and the tee-mounted boiler drain to power purge the air from the system. You push it all in one direction...It lets you power purge toward the system piping and up through the bottom of the boiler. You can power purge one zone at a time and never wind up with a big bubble of air trapped inside the boiler. This...often happens when you pipe your feed valve into the boiler and your purge valves on the return. You need that one main shut-off valve to get everything going in the same direction..."

(The installer likes to pipe feed valve into the return --instead of at ponpc-- to allow purging of zones with hot boiler water. Is there no other way to purge zones with the hot boiler water? I understand that there is some leeway in these situations, that each install configuration presents its own problems, that the expansion tank can be within a certain distance of the PONPC, etc. I don't necessarily want to make the installer's job more difficult if it can be avoided.

Note: This is for a 47K loss/100K gain 2-zone house. B&G EAS Air Eliminator to be used. Boiler is Buderus G-115/21 with ST-150.

Thanks,

David

Weezbo

it is not to your advantage to do so.

however , this is America and people have the right to try anything ,..Once:)

the ability to do something is not quite the same as knowing what the consequences will be...

the idea of adding water in other locations changes some details in the equasion as it were... the water feed may be added anywhere in a system however the preformance of the pressure changes within the system may vary signifigantly so much so ...that your boiler feed water pressure relife valve and circ pump ,and your patience may be getting far more exercise than you would like.

if you do add it in ahead of the pump and air scoop "stay close" as things will work better in the long run.

D107

how would you then purge zones with hot boiler water?

Thanks as always Weezbo, but how would you purge those zones with the real hot water without the feed (or feed valve) on the return? And how do you support heavy expansion tank from a 1/2" or 3/4" connection if it's not going to be on the floor?

Thanks,

David

Weezbo

the physical location of the tank....

is not near the trouble that the connection to the boiler system may be. in other words you can plug the feed water and tank in at the spirovent or just ahead of it then pipe to the tank or the fast fill and backflow.

you can pipe the tank to a wall or ceiling, the floor ... the room next door.... get a picture of the boiler in your fingers and look at manufacturers recommended locations for the boiler you have...any pipe arrangement that is made up tight on a boiler can generally be piped to another location where you have the space to secure it ...

Michael Welch

Fedder picture

This is how we pipe our water feeder on hot water boilers hope this help you out.
Mike Welch
Lyons Plumbing and Heating Inc.

Ted_9

Have your installer do it the way Mr Welch is showing.

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D107

Very neat, thanks. Would some consider circs then too high

for easy maintenance? I know some of this is personal preference or one disadvantage against another. (I have seen some posts where the expansion tank is on its side which generally seems ill-advised from all I've read.)

Thanks,

David

Unknown

Good question

And one I've been meaning to ask but somehow keep forgetting .

How far is too far away to pipe in the expansion tank upstream of the circulators ?

Personally , we pipe them within 8 inches or so of the circulators . Can there possibly be any issues with this distance ?

D107

here's a link from a recent post by Mr. Milne showing a lower

placement.

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=40518&mc=4

Steve_35

One question, Mike

Don't Spirovents require 12" of straight pipe before them like air scoops?

brucewo1b

Don't Spirovents require 12\" of straight pipe

No, as the air does not have to be at the top of the pipe to get the Spirovent to work it grabs the bubbles at all levels.