Two pipe system with air vents

Levie

Okay guys I have an interesting system here I have two pipes that every radiator but no traps and they all have air vents.  I don't have two valves on both sides like Dan shows in his book. The second pipe from all the radiators is just piped straight into the dry return.

Additionally I have a main steam pipe that's on the first horizontal run is pitched towards the boiler but after that it is just slightly pitched away from the boiler then somewhere 3/4 the way down the line it starts back pitching again.  Can I just add a drip line on the low point of this main pipe? I would end up having three directions of condensate first towards the boiler and then parallel and then counterflow again?

Additionally where my dry return drops to wet return it is on a 45 degree angle or less I am almost sure that's not okay but would want any input you have.
Thx

Levi

Levie

First picture is the 45° angle dry to wet return

Second picture is a radiator return side

Third picture is all those dry returns connected to each other 

Levie

Here's a picture of the low point of the bead pipe that I want to add a drip line to you can see a replace piece of pipe where there was water sitting so it had pin holes

Jamie Hall

No harm to adding the drip -- but is there any way you could rehang that section so it all drained in one direction or the other? In fact, I'd be mightily inclined to see about doing that, and adding hangers as needed (I don't think much of holding those pipes up with a sort of odd shelf...)

Levie

I removed some hanger to try to do that and I'm having a very hard time getting a reasonable pitch.  If the first section is pitch strongly towards the boiler is that an indicator at the whole system should have been counter flow? 

And do you think I will be able to raise the main pipe a full 2 in at the end without affecting all the radiators connected?

Levie

That pipe on what looks like a shelf is just really a 2x4 with a piece of wood that I pushed it to see if I could get a normal pitch.  It's before the last section of pipe and even with this wedged in I am still counterflow there also.
So the first section and last section are counterflow it's the middle that is pitched towards the end.

pedmec

is there a sudden problem with your system?

Levie

This property was bought a few years ago and always had issues.
First of all that low point in the main line is rusting out from the water sitting there additionally there is lots of noise when running
I just don't want to mess with the system before I fully understand what's going on.

Have you ever seen a two-pint system running for the same main pipe?

Jamie Hall

Levie said:

This property was bought a few years ago and always had issues.
First of all that low point in the main line is rusting out from the water sitting there additionally there is lots of noise when running
I just don't want to mess with the system before I fully understand what's going on.

Have you ever seen a two-pint system running for the same main pipe?

don't blame you for caution! There's no harm to a drip at that low point, although it's a bit odd. And no, I haven't seen a two pipe system with both feeds to the radiator from a main, but there's no good reason why it might not work.

Levie

I was wondering if that elbow leaving the radiator under the air vent in the picture was a orifice instead of a trap and maybe some plumber down the line piped the end of the main supply into the return line without putting a trap in then whatever thing stopped working he added the air vents.
This is my best hypothesis so far 

Steamhead

Levie said:

Here's a picture of the low point of the bead pipe that I want to add a drip line to you can see a replace piece of pipe where there was water sitting so it had pin holes

With regard to the pic in this thread- I would simply loosen the union to the right of the hook, crack off the elbow to the left of the hook and replace it with a tee with the run (straight line) paralleling the wall. Then add a 2x3/4" tee for a main vent, then a 2x1" reducing 90° pointing down, and pipe a wet return from there back to the boiler.

The radiator pic you posted earlier is actually cast-iron baseboard, which is certainly newer than the original installation. Can you post a pic of one of the older radiators, with close-ups of the shutoff valve (if you can find an original one with a lever that would be best) and whatever is on the return connection? I have a hunch this is some sort of Vapor system that's been seriously knuckleheaded.

Levie

Steamhead said:

Here's a picture of the low point of the bead pipe that I want to add a drip line to you can see a replace piece of pipe where there was water sitting so it had pin holes

With regard to the pic in this thread- I would simply loosen the union to the right of the hook, crack off the elbow to the left of the hook and replace it with a tee with the run (straight line) paralleling the wall. Then add a 2x3/4" tee for a main vent, then a 2x1" reducing 90° pointing down, and pipe a wet return from there back to the boiler. The radiator pic you posted earlier is actually cast-iron baseboard, which is certainly newer than the original installation. Can you post a pic of one of the older radiators, with close-ups of the shutoff valve (if you can find an original one with a lever that would be best) and whatever is on the return connection? I have a hunch this is some sort of Vapor system that's been seriously knuckleheaded.

I like your piping idea

I'll look to see if I could find any old radiators upstairs was occupied and I couldn't get it

I don't see any banana shaped or otherwise interesting parts near the boiler but I do see a check valve on the wet return near the boiler

Just two questions 

Can I run the drip line as a dry return and then drop to the wet later on?

Also if there is a vent at the end of that line do I must add one here too or is it just best practice?

Jamie Hall

I think I like @Steamhead 's idea. Take some more looking into. There may not necessarily have been any odd parts near the boiler -- or they may have been removed.

The two questions -- yes, no.

Levie

Thanks guys I'll let you know how it goes

One last question is there any issue running copper for the return?

Steamhead

Levie said:

Thanks guys I'll let you know how it goes

One last question is there any issue running copper for the return?

Not as long as no steam can enter it.

Levie

So I can use copper for a dry return as long as it's after the air vent?

mattmia2

No. dry returns can have steam in them in one pipe. You can really only use copper below the water line.

Perhaps that pitch is off because someone changed the height of the boiler end of the man when they replaced the boiler?

Is it possible those returns in the crawl space were below the water line of the original boiler which were usually much taller than a modern boiler? Ideally those returns would connect below the water line so that steam from one radiator can't enter another radiator through the return and to keep steam out of the return.