Single pipe - fancy condensate return

ChrisJ

I think I posted about this a long time ago, but it's been kind of in remission for 11 years...

I guess this section of the house is still sinking because the problem is back. I do need to fix the main issue, however......in the mean time until I can get under the crawlspace and start digging new footings I need a bandaid.

I have a single pipe radiator that has a bit of an issue with holding condensate in it's 10' long 1 1/4" runout. It's tight to the joists now as well as a PVC poop pipe so I've got no where to go, even if I decided to do some notching, the poop pipe is in the way. And that pipe, is important. It's not optional, trust me.

There's also another run out along side this one that has never acted up, YET. But, in case it does I'd like this to work for that one as well. This one was fine for 11 years and now it's clanking on a cold startup. I gained 1/16" with shims under the radiator, which seems to have solved it, for now.....

My thoughts were to run a 1" pipe to my "dry return" ( @Jamie Hall will love it!) and use a steam trap to keep steam out of the drain. Will this work? Should it work?

I'd tweak things to make the single pipe run outs pitched backwards (towards the drain and trap) rather than back towards the main like they are now.

If need be, I'd do the same thing on the other run out with it's own trap.

Here's a childish drawing I did real quick.

ChrisJ

Jamie Hall

OK, I'll bite... what is that "dry return" doing now? But if it is really a return no reason at all why that won't work fine. If it's actually a steam line, it depends a lot on getting a bit of head on the trap so that the float part of it will actually open. Probably will...

ChrisJ

Jamie Hall said:

OK, I'll bite... what is that "dry return" doing now? But if it is really a return no reason at all why that won't work fine. If it's actually a steam line, it depends a lot on getting a bit of head on the trap so that the float part of it will actually open. Probably will...

It's a return that connects to the end of the steam main and runs back to the wet return, 15 feet or so. It's after the main vents. I suppose my main question is, will that steam trap allow condensate to drain easily? I assume it'll be open when there's water puddling in it? Can they be used in any position as long as the steam hits the correct side?

ethicalpaul

At your pressures, you don't need a steam trap, you just need a p-trap

EBEBRATT-Ed

Agree with @ethicalpaul .

What you need is a loop seal (like a trap) Cut a tee facing down into the location where the water is located. Drop down as much as you need to make a loop seal that will hold your steam pressure. 28"/1 lb of pressure. Dropping more is no issue. The other end of the loop seal can go back to your return or go in to a supply main that drains back to the boiler. I would go into the bottom of the return or supply main. Dan describes this in his book

I would stay away from traps

ChrisJ

I thought about a water trap, but wouldn't that dry out in the summer?

And then what happens when I fire up ol Betsy....
Or was it Gladys?    In the fall?  

EBEBRATT-Ed

Contained within the system how can it dry out.? The water doesn't evaporate out of a steam boiler in the summer. Even if it did it would bang and fill on the first run. No moving parts nothing to go wrong. Cept a leak

ethicalpaul

Yeah that would be a lot of evaporation out of a #4 radiator vent or whatever

So at your running pressure Chris, you need like a 1/2" deep trap I guess. Make it an inch just to be sure

ChrisJ

ethicalpaul said:

Yeah that would be a lot of evaporation out of a #4 radiator vent or whatever So at your running pressure Chris, you need like a 1/2" deep trap I guess. Make it an inch just to be sure

Actually I guess that's a benefit of measuring with inches of water column.

My system is set to rest if it hits 8 inches at the boiler.  But..... The return isn't at atmosphere under those conditions... So do I need more than 8" of trap?

It would seem no.....

ethicalpaul

The return will be at roughly 8" when your boiler is at 8" and at roughly atmosphere during the rest period, right? I'm not sure I understand your question.

I'd probably put double your cut-out just to cover whatever...so 16" if you have it available.

And I'd put a sight glass on it to show how much it was getting pushed!

KC_Jones

Why do you need anything?

You are adding a condensate drip into a return. The water will flow, if steam comes up the other pipe, does that even matter? If this was connected to the other end of the radiator were the vent is I could understand the desire to do something, but being connected under the valve end, what does it matter? The condensate will flow with gravity and ignore the steam, just like it always does.

I feel like there is something obvious I'm missing at this point and I'm sure @ChrisJ will tell me.

Look at 2 pipe air vent systems. They had 2 pipes, no isolation between those pipes and everything worked just fine.

ChrisJ

ethicalpaul said:

The return will be at roughly 8" when your boiler is at 8" and at roughly atmosphere during the rest period, right? I'm not sure I understand your question.

I'd probably put double your cut-out just to cover whatever...so 16" if you have it available.

And I'd put a sight glass on it to show how much it was getting pushed!

KC_Jones said:

Why do you need anything?

You are adding a condensate drip into a return. The water will flow, if steam comes up the other pipe, does that even matter? If this was connected to the other end of the radiator were the vent is I could understand the desire to do something, but being connected under the valve end, what does it matter? The condensate will flow with gravity and ignore the steam, just like it always does.

I feel like there is something obvious I'm missing at this point and I'm sure @ChrisJ will tell me.

Look at 2 pipe air vent systems. They had 2 pipes, no isolation between those pipes and everything worked just fine.

@ethicalpaul
The system is at 0 when it's at atmosphere. As it's filling, there's very little pressure there. It'll never be 8" on one side of that pipe and 0 on the other was the point so why are you saying a 16" trap?


@KC_Jones I thought about that. I suppose my concern is the steam taking a short cut and going backwards up the return. Though I'm not really sure how a long cut through smaller pipe is a short cut. But sometimes it feels like things break the law of physics just to piss me off.

EBEBRATT-Ed

@KC_Jones

Wouldn't say that two pipe air vent "works fine" they can be horribly bad and are probably the easiest system for someone to screw up.

Not saying you are wrong technically they can work well but a loop seal is a sure thing and will work with no issues. Why risk getting steam somewhere you don't want it?

Besides, @ChrisJ likes to fiddle and a steam trap or two pipe air vent system is too easy lol

ChrisJ

Ok, so,
Here's my idea.......

The traps in my mind, are to encourage the steam to go where I want it to go.
Please excuse the crudity of this model, I didn't have time to build it to scale or paint it

ratio

Double trapped. Just don't rise up in between.

ChrisJ

EBEBRATT-Ed

Should be ok

mattmia2

KC_Jones said:

Look at 2 pipe air vent systems. They had 2 pipes, no isolation between those pipes and everything worked just fine.

I thought they usually had individual returns from each radiator that dropped down in to a wet return to separate them.

EBEBRATT-Ed

@ChrisJ drawing Should be ok

EBEBRATT-Ed

@mattmia2

I have seen both on 2 pipe air vent. Dropping all the returns to a wet return seals the return against steam and works fine,

But typical 2 pipe air vent usually has valves on rad inlet and outlets. The return is usually 1 pipe size smaller and is connected to a dry return. Problems can be steam comes through 1 rad and into return goes up the return of an adjacent radiator and closes the vent before that rad gets steam and leaves it air locked. It's all in the LAOSH