Steam main vent

drewander85

So I have a two pipe steam heat. At the end of the return line are two f & t traps. one coming from one half of house. The other coming from other half of house. Only one return line has Hoffman 74 vent? Shouldn't the other line have a main vent as well?

drewander85

Also my two pipe system has a vent and a steam trap...its not suppose to be that way is it. All my radiators are this way except some of the vents are at the top.

JUGHNE

Need a picture of the lower right side of the boiler, where does that drop pipe connect to?
Was that Hoffman 74 drilled and tapped into the pipe?

drewander85

It drops straight down to the bottom of the boiler tank. I also get water in my pigtail and it seems as if it it effecting my pressuretrol.

Jamie Hall

Looks like one of those systems which one looks at and wonders... what was it, originally? And what can be done to get it back to operation?

Can you post a photo of a radiator inlet valve? That might help to figure out what it was when it was new...

In the meantime this may take some fairly extensive - though probably not expensive -- work. The vents on the radiators shouldn't be needed. OK, but that assumes that all the steam traps on the radiators are working properly -- so probably the best place to begin is to check all the traps. They should let water and air pass, but not steam. Then the next question will be to find out how the mains are vented. They may have crossover traps going into those two dry returns. If so, those also need to be working properly. Any trap which isn't working right needs to be repaired (there are repair parts available for most traps).

Then the dry returns need to be vented It is quite likely that originally the dry returns all joined together and had all the venting at the boiler, where they now join after the F&Ts. With the F&Ts there -- which are very likely to be a later addition -- you will need copious main venting on both the dry returns. A couple of BigMouths, or several Gorton #2s should do it.

But lets see if we can figure out what it was supposed to be first...

drewander85

I don't see a Hartford loop and the Hoffman has a 1" T with a 3/4" bushing. There is also no f&t trap nor a main vent on the steam main only on the return line by the boiler like the first picture.

Jamie Hall

That poor little Hoffman was probably fine back in the day. It's not any more. But at least you have a big enough tapping to play with.

If there are crossover traps on the steam mains and drips to a wet return, you don't need vents on them, nor F&Ts. If there is no wet return drip, you do need the F&Ts and, most likely, vents.

drewander85

Ok here is the radiator they are all this way except up stairs they have the old Trane elbows instead of newer style radiator traps. I have order new steam traps for upstairs and repair parts for the traps downstairs

EBEBRATT-Ed

I am wondering if the two F & Ts were added later to "master trap" non working radiator traps.

@drewander85 the two return lines that go to the F & Ts are they connected to radiation with radiator traps and nothing else??

It looks like the fix would be to remove the F & Ts, fix all the radiator traps, remove all the radiator air vents. Then I would ty the 2 return lines together below the boiler water line and install a bigmouth vent on each return where the traps are now

JUGHNE

Your pigtail should have water in it, mainly it should be clean so the control sees the true pressure in the boiler, also the opening into the boiler should be checked.

Upper pictures of how the 2 mains are connected to the boiler,
maybe just stand back to include all the piping.

drewander85

There are no crossover traps down stairs at all. Just those f&t and that one vent. I also don't see a wet drip. Looks like all dry return no vacuum pump as well. All the white pipe is steam main. It borders the basement the equalizer pipe hooks into it further down.

Jamie Hall

Vapour system. One of those valves is a Hoffman; the other I'm not sure of the make, but also vapour, probably Trane.

Look very carefully at your steam mains and dry returns. There may have been crossover traps on them at one time. If there are no F&Ts or crossovers at the end of the steam mains, how are they vented? Are they vented???

Also this system is going to work best -- when you get it up to speed -- at very low pressures (ounces per square inch).

drewander85

I'm going to order a vaporstat once I have all the venting figured out. Most of my radiators have the Hoffman 40s. It looks like a union and nipple were put in where there use to be a crossover trap. In this picture that nipple and union are on the end of steam main. Just behind that picture is where the big steam main ends and is reduced to the smaller equalizer pipe. Then leads to that union and elbow.

drewander85

They took off that 12 ft length of insulation as well. Shouldn't it be insulated on that pipe till the boiler?

drewander85

This is where the steam main and equalizer pipe meet and you can see how it it starts then goes around. Borders the one half of basement and goes back to boiler.

drewander85

Here is a few more pictures of the steam main and where I talked about the union and nipple where I think a crossover trap use to be. Not real sure tough so I want to ask the professionals

drewander85

> @EBEBRATT-Ed said:
> I am wondering if the two F & Ts were added later to "master trap" non working radiator traps.
>
> @drewander85 the two return lines that go to the F & Ts are they connected to radiation with radiator traps and nothing else??
>
> It looks like the fix would be to remove the F & Ts, fix all the radiator traps, remove all the radiator air vents. Then I would ty the 2 return lines together below the boiler water line and install a bigmouth vent on each return where the traps are now

They are connected to radiator traps. And nothing else as far as I can see.

drewander85

I have 5 radiators on main floor and 4 on the second floor.

drewander85

I got the radiators taken care of with all new steam traps on the way then I'll take out the radiator vents . so what should I do to take care of the steam main. I got two big mouths for the return vents. And I take out the f&t traps and pipe them down below the water line and tie them together there. Anything else to get this thing in proper order? Thanks for all the help!!!

drewander85

@EBEBRATT-Ed is there a reason I would have to tie the two returns together after the water line? I have water supply plumbed into the existing pipe in copper. Can I just take the f&t traps put and tie it together on where it is already tied together?

Jamie Hall

@EBEBRATT-Ed has far more experience than I in the real world -- so I would be inclined to defer to him. However, that said, if those lines really are in fact dry returns, and never carry steam, they can be tied together where they are already -- without the F&Ts -- and a cluster of vents for the whole show. That makes the critical assumption that they really are dry returns and not, as is often the case, simply continuations of the steam mains back to the boiler. There's a lot of confusion on that -- and, in my humble opinion, misuse of the term. The critical thing to find out is to go through the system and make sure that there is nowhere that steam can get into them -- every possible connection has a trap, a water seal loop, or something of that sort.

Are there wet returns on this system?

drewander85

@Jamie Hall I don't see any type of loops. It seems as if the steam main supplies the radiators then the return lines go back to the basement to the f&t traps then to to boiler. I don't see any loops anywhere.

drewander85

@Jamie Hall Steam main borders basement then back to boiler. Then I just see return line. I am replacing of traps on radiators and got two big mouths. One for each return. Do I need anything for steam main?

drewander85

The drawing of the pipes are all on the ceiling. I don't see any loops so I'm pretty sure it's dry return

drewander85

A little more drawing

EBEBRATT-Ed

@drewwander

If the traps on all the radiators are working I see no need for the F & Ts.

If the F & Ts stay then you have traps in series ...at the radiator and then at the F & Ts which I don't think is good.

Now, if you take the F & Ts out then you need to vent the returns to get the air out.

I don't like the Idea of 2 return going into 1 above the water line if one return vents first and the vent closes the other return will have air trapped in it. Yes if all your radiator traps are perfect you shouldn't have steam in those returns so on paper it shouldn't matter.

If you do get any steam in the return from a questionable trap it will close both vents and screw things up

So you have 3 choices.

1.Leave the F & Ts and add vents downstream of the traps
2.Take the F & Ts out and install vents....this may work
3. Take the F&ts out put on vents and tie the returns together below the water line


To me #3 is a sure thing

Jamie Hall

Agreed. #3 is less elegant --#2 is the way it should be -- but although #3 is less elegant, it will work just fine -- on this system (unlike some) there doesn't seem to be any need to have the dry returns tied. So I imagine if I were turning the wrenches, I'd go with #3.

drewander85

@EBEBRATT-Ed Ok I will do #3. So I don't need to vent the steam main anywhere, just the returns?

drewander85

@EBEBRATT-Ed how far should the vents be from the boiler when I take out the f&ts? Where would be a good location ?

JUGHNE

I'm with Ed on #3.
Looking at your pictures was there a plug in a tee, it was with the hanging laundry near by?
And are there any other plugged tees in any of the piping in the basement?

drewander85

@JUGHNE There are no plugged tees but there is a place a union and a nipple were put in on steam main about 10ft from boiler Where it looks like a trap or vent may have been at one time. The picture with clothes is a reducer for the steam main to return to boiler then I turn around and take a picture where the union and nipple were put in.

Jamie Hall

@drewander85 -- may I just urge you, as you work around your system and get it working better -- be very sure that you clearly differentiate between a steam main -- which is directly connected to the boiler header at one end and which feeds steam to the radiators over at least part of its length, and a dry return, which has no direct connection to the boiler's header and which takes air and condensate from radiators (and, in the case of a system with crossover traps, air but not condensate, from the steam mains). A dry return may also have a water loop connection (going most of the way to the floor) with a steam main, which handles condensate -- this water loop may connect with a wet return in some installations.

The confusion comes about because in some installations a section of steam main after the last radiator runout does return to the boiler and connect with a wet return at the boiler. This is to allow condensate to drain properly. This section is sometimes referred to as a dry return. It isn't. It's still a steam main.

The difference is important. A steam main must be vented at the end, either with a main vent or a crossover trap, and must not form a loop (it also must be dripped to a wet return at whichever end is lower). Dry returns must also be vented, but there is no reason for them not to join together at the boiler above the water line (indeed, in some systems such as Hoffman Equipped, they must). Ideally, if all the traps are working or in orifice systems, the dry return vents should never close in normal operation (there are some systems, again, such as Hoffman Equipped, where they do close under some abnormal conditions).

drewander85

@JUGHNE I correct my self there is a plug in that tee. Sorry I missed that. That in on the return line.

drewander85

???? I'm trying to get all the parts to get this running properly. Any more help?

JUGHNE

Between that plug and the boiler are there any more taps, say return from radiator and anything else?
Is that the return without the air vent?

And is there a matching plug on the other tee, maybe hiding somewhere?

And are there any plugs in the steam main near that first plug or any other you might come across?

(I was wondering if I was looking at a gas pipe or not )

drewander85

@ JUGHNE Yeah that's a gas pipe. There are no plugs anywhere on the return nor main. Just on Hoffman 75 vent on one of the dry returns and that's it besides the f&t traps.

drewander85

There is old radiator traps that I'm going to replace all of them.

drewander85

So I have the returns and radiator traps figured out. What should I do with the steam main? Just let it all vent through the dry return? I looked all over there is no wet drip nor wet return. There is no crossover traps nor vents for the steam main. Any suggestion? Looks like something was taken out towards end of steam main but have no idea what. Right where the union and pipe nipple are. Should I put something back in there like a trap or vent?

JUGHNE

Are your 2 steam mains tied together other than the end of main/dry returns?
You should have 2 end of mains each tying into one of the return lines.
Perhaps some study/analyses of your piping diagram would create some revision on paper.

drewander85

Nothing goes low nor loops. It's all dry return.all pipes run on ceiling of basement till it gets to boiler. It's does angle down towards boiler. Second and third picture is by boiler.

Jamie Hall

Everything pitches back to the boiler? I'm going to be that were that union and pipe nipple are there was one upon a time a crossover trap. But it will serve as well to simply put a vent or vents at the end of the steam main.