Boiler expansion tank

[DekeT]

I had to replace my old expansion tank. The new one I ordered had the dimension wrong on the web site. It said 14in tall it was actually 16 inches. So I end up not able to fit the tank directly under the in-line separator which is the best place.

Instructions mention;
1) tank may be installed into any tee or other suitable tapping anywhere in the system
2)may be installed vertically or horizontally
3)do not install on a dead end pipe or in overhead joist space.

Caution for horiz install is less lifespan. If this were a floor mount tank(mine is not) you could use quite a long pipe to reach the tank. To fit in the space I offset the tank with 2 elbows and a 12 in pipe, 1/2 in diameter. Did I just create that "dead end" pipe by doing this? Do any of you hydronic experts see a problem with this install or should I just skip the 12 in pipe and use a horizontal mount? The only other option is too raise the vertical pipe coming out the boiler. Doable but major PITA.

 

[Rockhead261]

You're fine. ***** that your new tank is a bit too large, but you did what you had to do.

I wouldn't mount it horizontally myself. There's a rubber bladder in there that would be only partially covered with water. I'd be concerned that the top part would dry out. You're better off having it "wet" (like you have it).

A "dead end pipe" is an unused zone or something that doesn't see water flow. Your inline scoop is in the right place.

 

[Liquidplumber]

There is no problem with the way you have it.

 

[Steve in Mi]

I would have used corrosion resistant material for pluming it up. Hate introducing rust to the system - perhaps you're doing water analysis and treating your water, I don't.

 

[brewchief]

I would have used corrosion resistant material for pluming it up. Hate introducing rust to the system - perhaps you're doing water analysis and treating your water, I don't.

Boiler is cast iron as well as the airscoop that the tank is plumbed into.

As long as you don't introduce oxygen on a regular basis by adding make up water constantly it's a non issue.

I've done it the exact same way many times with no issues.

 

[DekeT]

Thank you for the feedback. I fired it up and pressure was stable and burners cycled on correct temperature. Top of expansion tanks was warm and bottom cool. Nice blue flame but the burner tops looked to have some small red spots at the flame base. I presume that means the annual cleaning is due. What I need now is a big red LED temp/pressure gauge, mounted on the wall, so I don't have to kneel down next to the dial with my magnifying glass.

 

[anthony666]

i regularly pipe them on he-pex far away from the air eliminator just to get them out of the way and so their weight isn't dangling off my near boiler piping

also even though the install say's they can be used upside down i try not to ever do that unless i absolutely have no choice, i can't help but feel it's an air trap, even if it's just air in the tee and fitting .. air is the enemy and must be eliminated

 

[brewchief]

i regularly pipe them on he-pex far away from the air eliminator just to get them out of the way and so their weight isn't dangling off my near boiler piping

also even though the install say's they can be used upside down i try not to ever do that unless i absolutely have no choice, i can't help but feel it's an air trap, even if it's just air in the tee and fitting .. air is the enemy and must be eliminated

I agree with not mounting upside down, at least one brand used to specify not to mount them that way.