Expansion Tanks

Alan (California Radiant) Forbes

I want to reduce my truck and shop inventory. Currently stock small and medium tanks for both potable and hydronic systems. They're large and take up a lot of room. I don't mind paying a bit more for a potable tank, but I'd like to find these tanks made with ½" connections and I seem to remember these being available, but can't seem to find them now. That would allow me to carry just one set of tanks. And I'm sure the potable tanks last longer than the non-potable ones.

Does anyone know a source for these?

EBEBRATT-Ed

Watts , Taco and Amtrol are all 3/4" as far as I can find.

JimP

Could you use a reducing coupling and 1/2” nipple for the heating application?

hot_rod

The Amtrol Radiant Pro is basically their Thermtrol with a 1/2" connection. However it doesn't have the NSF listing as a potable water tank. But same poly lined tank used in the ThermTrol.

ThermTrols are rated 180F, whereas the hydronic tanks are 200°. So use a ThermTrol only on low temperature hydronics.

Evan will be doing Coffee with Caleffi on June 25. Their family has been long time Amtrol reps and he does trainings at the Amtrol facility and helped build their training lab. So bring your expansion tank questions next week.

There is a movement towards flow thru DHW expansion tanks to prevent legionella growth.

Although Amtrol uses a turbulator on their DHW tanks to mix up that water in the tank, and antimicrobacterial liner.

The only 1/2" DHW tanks are those 1/2 gallon made for tankless water heaters, like the Zilmet stainless one. Larger commercial size DHW tanks actually go to 1" connection

Why not just keep a 3/4 X 1/2 stainless of brass bell reducer and nipple to use the DHW tank on hydronics?

mattmia2

wouldn't the schrader have to be leaking for that indicator cap to work?