venting question on one way steam system

bennythepitbull

the recommended near boiler piping shows this illustration (see below )
I have a very similar set up and want to add a vent.
My question is on the main vent , Is it okay to just terminate at the tee with a cap/plug or is the illustration missing something

JUGHNE

Where you have "terminate" labeled is where the return water would come back to the boiler.
It would be the end of the main (EOM)....sometimes incorrectly called a dry return....but it is an extension of the steam main.

If you have more than 1 EOM, then each must drop below the water line separately, (and be separately vented) into the wet return (pipes below the water line).

If you have no return....wet, dry or EOM...then you may have a counterflow system which is certainly a horse of a different color. Show us pictures of your new boiler install.

bennythepitbull

can the tee marked in yellow be used as dry return i would have 2 of them the other is right next to it just could not draw in well enough, i would run down to
to bottom to connect to Hartford loop

Jamie Hall

If the lines connect directly to steam mains, they must be vented and returned below the water line separately. You cannot join them above the water line. Each of them -- however many there are -- requires its own main vent, which needs to be before it drops down.

I'm not quite sure what the T you show in yellow is intended for. If it's a connection from another "return", then it won't work, assuming that the "return" is actually a steam main extension as noted above. However, looking at the drawing, it almost looks as though it's intended to connect to a steam main coming directly off the header -- in which case, the location of the vent is utterly useless, since the vent has to be at the other end of the steam main, not at the boiler end.

Have to admit that I'm not really happy with what I think I see in the background regarding the breeching from the boiler and some other appliance?

JUGHNE

First of all, how many pipes connect to your radiators?? one or two.
Next, the steam mains in your house. Where is the high point?

Is or was it above the boiler to where any water in the steam main would drain away from the boiler to the other end of the pipe....and then was there a pipe at the other end to return the water to the boiler?
This could be above or below ground.


OR, was/is the high point at the far end of the steam main with no return piping to the boiler from the end of the main and then in this case the condensate must flow back towards the boiler against the flow of the steam.

In the first case above that is Parallel Flow steam main, the steam and any condensate water flow in the same direction and the water return from the far end. (This is the most common seen here)


The second case is called Counterflow steam main. Steam out and condensate water back in the opposite
direction. (This does exist but not as often as parallel flow systems)

You must answer the 2 questions above in order to continue with your piping.
This is a critical point in your repiping/time to not make any mistakes of piping which will cause grief later.

I see perhaps 4 pipes at the ceiling for your boiler, where do they all go?

Note: that boiler looks new enough to have the install book available, you can google it if needed.

bennythepitbull

there is 2 and it is Parallel Flow, the top right corner of the photo is two elbows that are 2"
the top left is 2 2" unions which will receive two 2" black steel pipes (around 30" each) to complete the steam piping Just got to get in venting

bennythepitbull

let me get better angle of photo

JUGHNE

So you have return pipes from the far end of the steam mains.
They would be lower than the steam mains to allow for draining.
Those return pipes need to be vented somewhere after the last rad connection.

How many pipes are connected to each radiator????

EBEBRATT-Ed

@bennythepitbull

The vents don't go on the steam mains at the boiler. The vents go on the far end of the steam mains just before they reduce in size and connect to the returns.

bennythepitbull

I am only am asking this because I kid you not the old boiler had 2 vents attached right behind the boiler they were they were the only two vents in the whole system and it worked great for 25 years no hammer no nothing

bennythepitbull

EBEBRATT-Ed said:

@bennythepitbull

The vents don't go on the steam mains at the boiler. The vents go on the far end of the steam mains just before they reduce in size and connect to the returns.

after some research looks like I'm dealing with a one pipe counter flow -- the above is the fix to my issue, problem solved thanks all

EBEBRATT-Ed

@bennythepitbull

If it is counterflow the vents still go at the far end of the main

bennythepitbull

you know it

JUGHNE

Also, being counter flow, the steam mains need to be dripped at the boiler so all the condensate does not run back down against the steam leaving the boiler.

Your picture you had up showed a tee drawn in that was somewhat like a "drip" for the horizontal mains.
The picture is gone now.

You can find counter flow steam piping diagrams with drips on line somewhere or in the install books.

This is the easy time to install them.

bennythepitbull

hey I got ya I'm gonna build it, it is actually what my old system had. I only have this photo to show as an example of what you are talking about. I am going to replicate this : any thoughts?

KC_Jones

If I am interpreting what you have correctly, that last picture shows a vent, that shouldn't be there. That is not the end of the main on a counter flow system.

Follow the main steam pipe until it ends somewhere else in your basement, that is where the vent is supposed to be. If you pipe one in where that boiler is, on a counter flow system, is a waste of time and money.

The picture you posted at the beginning of this is a parallel flow system, it appears you have counter flow and that isn't the proper diagram for your application.

bennythepitbull

here is a photo of counter flow drips : keep in mind I know to put vents at the end of the main but ?

I drew in two yellow vents my old one had vents right there
should there be vents there or is my thinking off
if they don't belong why were they on mine ?


based off the photo it looks like the below example could work
see photo below

KC_Jones

There is absolutely no reason for vents there on a counter flow.

As to why they are there, hang around here long enough and nothing will surprise you anymore. It's hackery by someone who didn't know what they were doing, or looking at.

Jamie Hall

Just try to consider what the vent is supposed to be doing: allowing the air to get out of one end of a steam main while the steam is trying to get into the other end.

Now... if you put the vents at the beginning of the steam main, of what use are they? None at all. Just because someone put them there sometime back doesn't necessarily mean it's correct -- as @KC_Jones said, nothing much surprises us anymore in the way of odd arrangements which never worked right.

I am, however, still just a bit concerned, since I'm not sure that there is a clear understanding as to whether this system is intended to be counterflow or parallel flow, and whether any drips or terminations might be located. There are parallel flow systems -- a lot of them -- where the steam main loops around and comes back near the boiler and then drops to the return -- but doesn't reconnect to the header at that location.

There are also systems -- a lot of them -- which had a new boiler put in sometime in the past and repiped incorrectly, so they are part parallel and part counterflow.

In fact, one thing we've learned is that there is no end to the ingenuity of hacks...

JUGHNE

Can you back up for pictures and show more of the piping above the boiler and where it goes.
There is a smaller pipe up near the ceiling....what is that going to?
It looks like some cast iron fittings on piping on upper right....again what is that?

And a shot from far back showing the front of the boiler with your new piping so far.
We can't see if you are using both boiler risers or not.

Also the very end of the mains, again back up for more view.

No yellow added please.

bennythepitbull

Jamie Hall said:

Just try to consider what the vent is supposed to be doing: allowing the air to get out of one end of a steam main while the steam is trying to get into the other end.

Now... if you put the vents at the beginning of the steam main, of what use are they? None at all. Just because someone put them there sometime back doesn't necessarily mean it's correct -- as @KC_Jones said, nothing much surprises us anymore in the way of odd arrangements which never worked right.

I am, however, still just a bit concerned, since I'm not sure that there is a clear understanding as to whether this system is intended to be counterflow or parallel flow, and whether any drips or terminations might be located. There are parallel flow systems -- a lot of them -- where the steam main loops around and comes back near the boiler and then drops to the return -- but doesn't reconnect to the header at that location.

There are also systems -- a lot of them -- which had a new boiler put in sometime in the past and repiped incorrectly, so they are part parallel and part counterflow.

In fact, one thing we've learned is that there is no end to the ingenuity of hacks...

my guess is they wanted to create a vent to allow the drip lines to flow more smoothly, like when you put a hole on each side of a can so the liquid flow more smoothly again just a guess any way I will eliminate

KC_Jones

bennythepitbull said:

Just try to consider what the vent is supposed to be doing: allowing the air to get out of one end of a steam main while the steam is trying to get into the other end. Now... if you put the vents at the beginning of the steam main, of what use are they? None at all. Just because someone put them there sometime back doesn't necessarily mean it's correct -- as @KC_Jones said, nothing much surprises us anymore in the way of odd arrangements which never worked right. I am, however, still just a bit concerned, since I'm not sure that there is a clear understanding as to whether this system is intended to be counterflow or parallel flow, and whether any drips or terminations might be located. There are parallel flow systems -- a lot of them -- where the steam main loops around and comes back near the boiler and then drops to the return -- but doesn't reconnect to the header at that location. There are also systems -- a lot of them -- which had a new boiler put in sometime in the past and repiped incorrectly, so they are part parallel and part counterflow. In fact, one thing we've learned is that there is no end to the ingenuity of hacks...

my guess is they wanted to create a vent to allow the drip lines to flow more smoothly, like when you put a hole on each side of a can so the liquid flow more smoothly again just a guess any way I will eliminate

Not a correct analogy, but I see people think like that on steam all the time.  Those drips aren’t full of water so there isn’t any gurgling or venting needed.  Also, as soon as steam hits the vent it closes, so in that location it would only be open for a minute, maybe seconds.  The condensate wouldn’t really be flowing at that point.

Jamie Hall

I think one of the things which sometimes mystifies people with steam is just how little water is really involved -- take the big boiler I play with, Cedric. He really is fairly good sized as residential boilers go. And, at full song, he evaporates (and the system condenses) all of two quarts of water per minute... which is about a tenth of what a usable shower uses.