Mystery Loop?

tlowc34

Hey SteamTeam, I've always wondered the purpose of the loop pictured below. It is at the end of my longest steam main, after the vent, right before it dives down to the wet return to the boiler. None of the other two steam mains have loops like this (or a trap for that matter) before they drop into the wet return. The only thing I can see that makes this main unique is the wet return it drops into has to cross a doorway so it drops into the floor before resurfacing and meeting the returns from the other side of the house and heading into the boiler.

tlowc34

Also, why would you make that joint with a Tee. That condensate can never get out and will rust out that extension, right? Reminds me of the sediment trap on a gas line.

Hap_Hazzard

Sediment trap is exactly what I was thinking, but is it necessary? Probably not. If you take it off, I'm pretty confident you'll find sediment in it, but sediment is just a fact of life in wet returns, and there's no reason for putting it where it is if it's just a sediment trap. It would make more sense to put it at the bottom.

Offhand I'd say that the reasons for this configuration a purely historical, but the history that accounts for it is far from clear from the evidence, though one of the pros here might be able to shed some light on it.



Do you know what the object shown in this picture is?

tlowc34

That object is a Trane B-3, similar to the condensate traps on my radiators (Trane B-2's)

JUGHNE

The loop looks like a cooling leg for that trap.
But why do you need a trap there?

After this picture does the piping rise above the water line anywhere down stream?

tlowc34

To keep hot steam out of the return? I don't know, it never rises above the water line after that drop.

tlowc34

I also thought about that cooling functionality, but wouldn't the trap accomplish that without the need for that wide loop?

Jamie Hall

There's some lost history behind that somewhere. Like... I wonder if there was a wall mount radiator there? Or.. I don't know!

Steamhead

That system didn't have a trap there originally, but someone added one.

Did someone also add a condensate tank and pump to this system?

tlowc34

It's in a basement laundry, maybe it is a clothes drying loop? I don't know - grasping at straws.

mattmia2

Is that a left/right coupling just to the right of the trap? Getting that loop there after the system was piped would have been difficult otherwise.

That pipe on the top looks like it was put there after the pipes were painted but the other joints don't look like they have been unscrewed after they were painted so that doesn't exactly make sense.

JUGHNE

The trap has a union to allow all that to be put together as such.

tlowc34

The paint is asbestos binding compound. Meaning if it is white it was not covered with asbestos when the encapsulation happened. Not sure if some fell off before they got to it. But that would support the laundry rack hypothesis, open on the bottom to hang clothes over. But wouldn't it make sense for it to be chrome plated or brass? Who wants to hang clean clothes on dirty black pipe? @JUGHNE is right about the union.

tlowc34

@Steamhead, no condensate pump. It's all gravity return. But closer to the boiler there is one of those strainer/trap looking wyes on the wet return coming from these.

tlowc34

@Steamhead - Also, I agree that it looks like it was added later, but why wouldn't the original installer run the same size pipe for that whole drop? It looks to be 1-1/4" coming off the main but 3/4" at the bottom. They could have put a reducer in that original run, but seems unnecessary. Here's a high res version

AMservices

I think @Jamie Hall got it. There was probably a wall radiator there.
I also think @Steamhead is right that it's not original to the system.

Someone, at some point, decided they want heat in that room. Probably around the time the Laundry went in.
They hired a heating expert that knew 2 pipe steam needs steam traps and not air vents on the radiators, so that's what they got.
Radiator never worked right because steam traps have to vent air into a dry return. That trap is going into a wet return. And air doesn't vent well through water.
A few years and a few heating experts later, the owner was sick of looking at the radiator he paid $,$$$ and never worked, and he finally paid someone to do what you see today.
It's a shame, If they had only put an air vent on the radiator and left out the steam traps, it probably would have worked great!


I cant say for sure that is exactly how it all went down... But that's the story I see.

AMservices

The 3/4 pipe was probably original because that was only a drip for the end of the main.
Didn't have to be 1-1/4" like the pipe on the left because that's the drain for the end of the dry return.

DanHolohan

@AMservices, I agree.

tlowc34

So, remove?

AMservices

> @tlowc34 said:
> So, remove?

Is there any water hammer?
If not the easy thing to do is leave it alone.

Or maybe put a air vented radiator in and finish the job

tlowc34

@AMservices - There's some, but I believe it's more due to my near boiler plumbing. I'll be correcting that, but right now I'm putting on the insulation and looking to make sure everything is correct. I'm confident I'll be able to handle this job. My Only concern is the pipes are slightly misaligned. I need to move the Tee about 5 degrees clockwise, which I doubt I can accomplish without taking it off, cleaning up, and reinstalling (with pipe thread sealant / tape). I haven't ran into any rotted plumbing outside of 1/2" condensate return plumbing and a spud I relied on to hold a pipe while I unscrewed some other pipes that were connected.

AMservices

Any time I'm taking apart old pipe, I always try tightening it first. 90% of the time it works. Just get it to move a little to the right and it comes out, no sweat.

Steam speed

DanHolohan

I’d remove it. it serves no purpose.

tlowc34

Thanks for the help everybody! I’m pretty proud of this one. Got the old stuff out, cleaned, and everything put back together in 90 minutes (I’m a relative noob). Didn’t break the tee that I desperately needed, since I was operating without a safety net (no backups) on the night before the coldest day in Michigan this fall. Only thing I wish I had thought of when I was at the hardware store was switching the bottom elbow for a tee with a plug to clean out the mud leg. That’s a quick 15 minute job to change though, thanks to the union.

@DanHolohan @Steamhead @AMservices @JUGHNE

Hap_Hazzard

tlowc34

@Hap_Hazzard I have a question on the header in your signature: how do you get the equalizer into the boiler? That header to equalizer joint has to be 90 degrees since it’s an elbow and with the downslope of the header that means the equalizer won’t be plumb, right? Is there a swing joint somewhere I can’t see?

Hap_Hazzard

That elbow is directly over the end of the return pipe.

tlowc34

So the angle between the header and the equalizer is greater than 90 degrees?

Hap_Hazzard

No, it's 90°. I guess it's not perfectly plumb, but it's long enough that it isn't noticeable. It goes into a tee at the bottom, so it's pretty close to plumb at that end. Black pipe is bendy.

SeanBeans

@tlowc34 you could also use the reduciNg elbow for your equalizer pipe at a 45 degree angle. That way when you use a 45 to straighten down it can be perfectly plumb

tlowc34

Could you do a swing joint at the end of the header at the same size of the header and then drop vertically into a reducer?

Hap_Hazzard

You'd need a couple of 45s to make it perfect. You're going from a header that's slightly slanted, down to a return that's horizontal (assuming the boiler is perfectly level), so you'd need to rotate the two 45s to come up with the exact angle you need.

But why bother?

tlowc34

It's either called Obsessive Compulsive Disorder or being anal retentive, depending on who you ask

I was thinking a 4" 90 perfectly horizontal > 4" close nipple > 4" 90 clocked perfectly vertical (plumb) > 4" nipple > Reducer > 2-1/2"

Hap_Hazzard

I've made pipe nipples bend at arbitrarily small angles by cutting them on the diagonal, rotating them to the desired angle and then welding them back together again. If you're interested I can post some pictures, but not in this thread. We've drifted far enough already.

BTW, you know that the header shouldn't be perfectly horizontal, amiright?

tlowc34

Yeah, that’s why I’m trying to figure out how to get back to vertical for the equalizer. It seems most just put that reducing elbow under strain and force the 90 degree joint to open wider / slightly bend the pipe to get the equalizer vertical. That kinda worries me.

SeanBeans

@tlowc34 go with the reducing 90 on the 45 and then a 45 straight down plumb. The double 90 might end up looking weird. Just my opinion though, yours may differ!

SeanBeans

I used to get upset that the equalizer wasn’t straight down, but then I realized that steam piping is all about pitch and it wasn’t a big deal as long as everything was piped correctly

JUGHNE

After the reducing ell then drop with 2 45 ells which can correct this and make it look proper.

Hap_Hazzard

I hope you guys aren't implying that there's anything wrong with the way my header looks. I mean, I built it to give me dry steam, but still, is it not a thing of consummate beauty?

tlowc34

No, it's purdy!

ethicalpaul

I thought he was asking how you are able to have a downward pitch on the header, and still be able to attach to the vertical equalizer pipe.

I've wondered that in the past myself...how to slope the header