Merging steam mains, tilted traps and general nonsense

Gateacre

This one is hard to explain, but here goes.

2 pipe steam. 1893 commercial property with multiple tenants on 2 floors. I've got a 5" main running south to north.

A 1 1/4" line comes off the main at ceiling height and enters the back of a ground-level art gallery from the east. It immediately feeds a rad in the store above and one in the gallery.

These both drop into a pumped return in the concrete floor. 1 1/4" continues westward.

At this point I'll mention that some hero didn't have the height to install the ground floor radiator traps properly and got creative. Probably the same genius that put vents on them.

The 1 1/4" continues West, tees off to a second radiator in the gallery.

Here we find more unconventional trap orientation and another single pipe vent.

Now it gets strange. The 1 1/4" is reduced to 3/4", continues West, takes a left turn to the south and begins running alongside a separate 1" line entering the gallery from the north (branched off the same 5" main but accompanied by a dry return).

The 2 steam lines now twine around each other like a mommy and a daddy snake trying to make a baby snake, merge, continue as 1" to the south end of the gallery, feed a second radiator in the upstairs store and stop with no end of line trap.

So…

The rads in the gallery and the first rad in the store get screaming hot. There's no trap for the steam pipe to vent though, just the sideways traps on rads.

1. Is there any chance that traps oriented like this would ever have functioned? Would they have always have let steam whistle through? Failed quickly?

The rad upstairs at the end of the line gets no heat whatsoever. I haven't opened its trap yet to see if it may be failed closed.

2. Is joining 2 lines like this ever a legit practice? Is there any purpose it could serve?

3. Can I leave it as is, add an end-of line trap and vent the whole thing into the dry return?

4. Once I install straight-through traps on the ground level rads, I assume I'll lose most of the initial venting for the 1 1/4" main. If the answer question three is yes, would I still likely need a crossover into the low return or would the end-of-line trap be enough?

5. What would we suggest as an end of line trap? Even a small F&T feels like overkill on such small lines especially once I have them insulated. Might a 1" thermostatic cut it?

If you're still with me and awake, thanks so much for following along and I would greatly appreciate any input you all might have.

Cheers

Jamie Hall

It'll take a while to process that one…

First question. Where do the returns on those radiators with traps go? If they go into a DRY return, where does that go? Back to the boiler? Is there a nice big vent on it there? If all that is so, the only reason they might not work is that odd trap orientation, or there not being adequate pitch for condensate to drain. But — the traps should work; they don't depend entirely on gravity. Usually. They should at least close on steam — but they may be a bit wonky on condensate.

I love the entwined mains. Weird. But if they are both steam lines, just that. One does wonder why…

Main thing is to trace every return and see where it goes and make sure wherever it goes is vented. And to feel them when the system is running — they might be warm, but never really hot.

Then also look at the main venting and dripping. By far the simplest and most reliable approach is to make sure any drips go to a wet return below the boiler water line, and that they can vent — preferably through a crossover trap into a dry return…

EBEBRATT-Ed

Put the rads up on blocks and pipe the traps right and rebuild them.

In the 7th picture down with the "double line" I would suggest that maybe the steam comes in from the right and feeds the tee, then elbows around and goes back in the chase.

If the steam in that smaller line is flowing the way you suggest with the 2-elbow riser it would hammer like crazy and hold water I would think unless it is dripped somewhere.

It's easy to get mixed up tracing pipe when you can't see the whole thing.

Not saying you couldn't be right, look what they did with the traps.

Gateacre

https://forum.heatinghelp.com/discussion/comment/1833088#Comment_1833088

If it takes a while to process, imagine how much fun it was trying to explain 😆.

All the returns are pumped and the return tanks (3) are vented.

Since there is no other way for air to leave the line that feeds those radiators other than through the sideways traps and the rads heat with unusual speed, my suspicion is that both 'sideways' traps are failed open. There's also what seems to me like an excessive amount of condensate returning to the boiler room which I'd expect if steam was getting into uninsulated 3/4" returns running 50' through a cold concrete floor.

I wonder if half of the trap element being perpetually immersed in water would keep it cool enough that it can't expand fully.

I'm replacing them with mepco straight traps but when I do, I won't have a vent for the steam line.

I think the best solution is going to be to disentangle it from the other steam line and instead cross over into the overhead return in pretty much the same place.

Gateacre

https://forum.heatinghelp.com/discussion/comment/1833093#Comment_1833093

Ed. I could elevate the rads but the tees in the returns are angled up somewhat and I'd like to avoid as much tear up as possible. If I double back from the end of a straight trap with 2 ells and match the angle to the nipple with a third, I think it should be possible.

I see what you mean about the 7th photo. With everything painted white, it's not easy to see. I am positive however that it's as I describe. No steam runs in the chase, only crosses through it at right angles. I've traced out all the lines very carefully and have had to open some walls to do so. There is, in fact, pretty significant hammering in that space. I'm not sure I understand how the arrangement you see would cause that but or really what other effects it would have, good or bad. I know it doesn't look right though.

Most importantly, there's no way for air to get out of the way of the steam as it makes its way to the upstairs radiator. As a result, steam doesn't get to that radiator at all.

As I said in response to Jamie, I think the simplest solution is to reconfigure that merger of steam lines into a crossover to the return (taking care of venting the first line). Then construct another crossover at the very end for the second line. I don't see any other option really.

Such weirdness.

EBEBRATT-Ed

Such weirdness. LOL @Gateacre

I don't doubt what you are saying you have seen the whole job. Most of the old timers got steam right but building get remodeled, and additions put on and that is when thing go squirrely sometime.

They think they put in enough money to do the job and halfway through find out they are short of money and then anything goes.

The radiator traps are a dead give away that someone didn't know what they were doing.