What's this tank

Craig Drabenstadt

Working on an old hot water boiler with radiators when I noticed a tank above the boiler simular to a standard expansion tank except it has four pipe connections and two air purge ports. The connections are labeled and piped accordingly. The Pipe ports are labeled from boiler and to boiler tapped on the bottom of the tank one at each end and the other pipe ports are labeled to system and from system tapped out of each end of the tank at the bottom close to the boiler pipe connections. The air purge ports are located about 2/3 up on each end of the tank. There is only one circulator on the system and all radiators get hot water to them when the circulator runs. What was this tanks purpose and how does it allow flow to the radiators. Someone added a diaphragm tank on the system when they changed out the boiler.

Big Ed

In System Expaintion Tank

I have seen one many years ago that was also not hook up . The reason why....it was made of steel not brass or copper What I understand is that it did not work well. This came up before I can't remember the logic...... Hello Dan !

Einsiedler_2

not buffer?

almost sounds like a buffer tank.

4 connections - 2 to boiler (supply/Return) & 2 to system (supply/return).

is there a sensor or aquastat on this tank?
what size is it??

Craig Drabenstadt

What's this tank

The tank is aprox. 10" Diameter X 24" long and does not have any thermostat or aquastats on it.

jeff_51

whats this?

have you stumped everybody?????