What's this tank for on this Steam Boiler?

[Neal Lewis]

This is a newer gas fired single pipe steam boiler. The water feed is connected to the tank, and the return is also connected to the tank. There is a circulator pump for a takeoff zone. The takeoff zone piping isn't connected to the tank. Any ideas what the tank is there for?

Also, the Unimatch automatic feed valve is on it's side. The manufacturer specifically states the auto feed should be upright, yet I see this installation constantly. And this one was inspected by the building dept. Is there any adverse effect by installing it on it's side?

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[kurt]

Are those Shark Bite/quick connect fittings on all that copper?

[Neal Lewis]

Yes, like a ProPress fitting. First time I've seen them on a steam boiler.

[kurt]

Well, now I'm mystified by two things.

The tank is curious, the copper and ProPress fittings strange for a steam system.

[Bill Kibbel]

For a "modern" steam boiler install, the most common reason for adding a collection tank on the condensate return is that the condensate is too slow in returning to the boiler. It's considered fixing a symptom but not the problem.

I'm guessing this is a replacement boiler on an old piping system.

[Rob Amaral]

Let's see.. auto-fill valve and manual fill valves are 'closed' (unless unit is calling to fill the boiler)..

-Galvi tank is filled in between 'fills' of low-water calls.to the top?.

-Tank top (filled-state) is 'at or just below' (?) the boiler water level...

-There's a hydronic zone off that boiler below the water level... (Doesn't matter)

-Hartford return clearly in view... (normal)

When boiler is in a 'low-water' state and calling on the auto-fill, there probably is an air-gap at the top of that galvi tank..

"boiler-fill water hammer arrestor"? (Those auto-fill valves can be noisy..) Odd..