Wet return reroute question

tim smith

Bit of a dilemma on this 50 unit steam system I have been working on. Finally figured out the contractor who did the boiler replacement cut a section of wet return that passed through a raised drain pit. Now dumping the condensate into the pit. I can see a section of pipe that continued around boiler room and came back into old boiler return. Pipe not there anymore. But can visualize. All the other dry returns come in boiler room overhead and the tied them into a manifold above feed tank then into feed tank. All return water is pumped back to boiler currently with no equalizer line. The return I need to redo is below water line of boiler, Not sure with no equalizer and hartford loop what will be the best way to get the condensate back to boiler. Inlet connections on feed tank too high. Any ideas short of installing a condensate receiver and pump? Not my favorite option. Btw probably needs at least a 2-1/2 equalizer I think if going that way. 2 million btu, 6" steam main.
Thanks,
Tim

tim smith

Here is a simple drawing of whats there.

tim smith

Jamie Hall

tim smith said:

Here is a simple drawing of whats there.

Didn't load, @tim smith . However, seems to me that you may not need a pump at all-- what is the height relationship of that feed tank to the amputated wet return and anything connected to it? If the wet return were connected to the feed tank, it would bee flooded -- not really a problem, as it should be anyway -- but where would the water stand in the drips that come down to it? Would water standing at that height be a problem? If not then I'd just figure some clever way to reconnect it back to the feed tank...

I'm a bit concerned about two other things, though. You way all the dry returns are connected to a manifold above the feed tank. Are these really truly dry returns? Two pipe steam system? If so, that's just fine -- a very good arrangement. If they are actually steam main extensions, not so good -- see some of my previous rants about the distinction.

I'm not sure the lack of an equalizer is really a problem. What it usually does is -- as the name suggests -- make sure that the pressure in the dry returns is the same, more or less, as the pressure in the boiler, and also to return any condensate from the header (if any) to the boiler. If you have a pumped feed tank,, though, and no direct connected wet returns, then presumably there is a check valve on the feed line from the pump to the tank and the boiler pressure can't force the water out into the wet returns and the rest of the system anyway.

ethicalpaul

What it usually does is -- as the name suggests -- make sure that the pressure in the dry returns is the same, more or less, as the pressure in the boiler

Respectfully, it doesn't do this. The main and the wet return itself do this.

Jamie Hall

ethicalpaul said:

What it usually does is -- as the name suggests -- make sure that the pressure in the dry returns is the same, more or less, as the pressure in the boiler

Respectfully, it doesn't do this. The main and the wet return itself do this.

We're both right. It depends on how fast the steam is moving -- if at all -- and the pressure loss in the mains -- if any.

ethicalpaul

I made a video where I installed a ball valve right on my equalizer and had sensitive pressure gauges at the boiler and at the "far end". Opening and closing the valve during different times of the heating cycle resulted in no change to any pressure anywhere in the system.

To paraphrase Henry Gifford, the equalizer does no more to equalize the pressure in a system than a hollow beer mug handle does to a mug of beer.

tim smith

Jamie, this is a 2 pipe, and the dry returns connect to the manifold above the feed tank. Discharge does have a check valve on it. I am a bit concerned about pushing water up to the cross over traps that are down low in the basement apts. Dimension is close to where the lines tie to the feed tank.
Thanks again for all of your responses. Maybe this pic will load.
Tim

Jamie Hall

Equalizer or no equalizer, that concern about the crossover traps is valid. The dry returns will be at atmospheric pressure or very very close to it. The steam main will be slightly below boiler presure, so there is no problem with water rising in the drips from the steam main -- but there could be in the drips from the dry return, if the dry returns have drips (not all do, though most of them do). That rise will be our familiar 28 inches for every psi at the boiler.

Jamie Hall

and ps -- that assumes that the wet return goes to the boiler. If it goes to the feed tank and the feed tank is vented to the atmosphere -- no problem.