Missing F and T trap

MadisonMatt

Hi All,

I have been in my 1923 house for a year and noticed that my 2 pipe steam system has no connection between the mains and the dry returns.  The ends of the mains appear to just be capped off but are very near the start of the dry returns which also appear capped.  The pipes and caps all appear very old.  Of course I can not find any F and T traps as well. 



System seems to work so so, with relatively quick heat up, but radiators rarely get hot all the way across, and upstairs always much cooler than first floor, though that may be a factor to the inadequate attic insulation. 



My question is whether this is a problem or just a different system than I have read about?  Also, the thermostatic valves on the radiators appear to be the originals in most cases, and I have Dunham packless lever handles on most of the radiators.



I can get pics if helpful.



Thanks all,

Matt

Steamhead

The usual Dunham

has a radiator trap piped between and above the end of the steam main and the dry return. This vents air from the steam main into the dry return, but closes when steam gets there. The air goes thru the dry return and out thru a Dunham Air Eliminator which is mounted near the boiler and Return Trap if there is one.



Take some pics of the end-of-main areas and also of the boiler area and post them here so we can see what you have.

The Steam Whisperer (Formerly Boilerpro)

Also....

You need to figure out where the condesate water from the steam main is going.  usually there is a drip line downto thewet return to handle the water, while air goes up into the dry returns.

MadisonMatt

Pics of system

Steamhead and Boiler pro.



Here are the pics.



Matt

MadisonMatt

Steam mains

Thanks for the quick replies.



Here are the far ends of the steam mains (third try).



Thanks,

Matt

Rod

Pipe Identification

Hi Matt- 

I'm having a bit of a problem figuring out what exactly we are seeing in your pictures.   I've labeled the pipes in some your pictures so that maybe using the labels, you can identify for us what they are and what they connect to.  

- Rod

Dave in QCA

which way to the mains slope?

It is difficult to tell, but it appears that your steam mains, and returns slope upward from the boiler and that the plugs at the end of the lines are the high point.  Is that correct?

MadisonMatt

Picture ID

Thanks again guys.  I will do the best I can on the identifications.  The mains do indeed slope back to the boiler, with the ends at the high point, so I assumed the condensate in the mains just flowed back to the boiler.  Also, I am suspicious that I have an issue with the boiler water as I see heaving in the gauge glass when the boiler is going.

I apologize if I use incorrect terminology, and I am at work so going off memory, though pretty confident on my labels.

H & G are the main returns.

F is the common return.  On the other pic you didn't label, you can see where it comes in between the red and blue stop cocks near the floor.

C & D are the same pipe, a riser off one of the mains.

A & B are the 2 steam mains.

E is the gas supply line

J is the end of one of the steam main #1 (can't remember which I labeled which)

K is a riser

L is the end of one of the return mains

M is a return condesate line from the radiator supplied by K

N is the end of steam main #2

O is the end of main return #2, it has a bullet shaped stubby extension on it just past the last return line that comes off it.  The other return main doesn't have this.

Thanks for all the help.

Matt

Rod

2 Pipe steam - Pipe Schematic

Hi Matt-

  Attached is a drawing that maybe of help to you in figuring out your system. There are several piping configurations possible on a 2 pipe steam system. I've tried to cover two of them in the drawing.  In the drawing there are individual main vents and drip lines on both the Steam Main and the Return Main. If there are more than one steam main each pair needs to be setup this way. Notice that the drip lines don't join together until they are in the wet return before the boiler water line. (Drip lines should not be joined together above the waterline as this "short circuits" the system)



In this configuration steam from the boiler enters the steam main and pushes the air out the main vent at the end of the Steam Main. When steam reaches the main vent on the end of the steam main, the vent closes and steam then enters each of the radiators. Any water (condensate) in the steam main flows to the end and down the drip. 

The steam entering the radiator forces out the air into the Return Main and out through the main vent on the end of the return main. Condensate from the Radiator flows to the drip line at the end of the return Main and back to the boiler via the Wet Return.



On a 2 pipe system another configuration is using an F&T trap which allows condensate and air to pass through from the Steam Main to the Return Main but keeps steam in the steam main from flowing to the Return main.  I illustrated the F&T circuit  in green. With an F&T trap, the dripline on end of the Steam Main and the Main vent on the Steam main would be eliminated. I generally favor each line having its own drip and main vent as this eliminates the need for the F&T trap. Traps are mechanical and mechanical things break down so if you can eliminate them so much the better. However there are situations where using an F&T trap simplifies the piping and is a more practical solution.



Thermostatic tarps on each radiator -You need to make sure that each of these is working properly. There are rebuild parts available for most traps (even very old ones).

- Rod

Matt- I posted this before I saw your latest reply. Thanks for the info- will go over it tonight. Your mains being sloped back towards the boiler seems rather odd. They should be higher where the steam enters the steam main and slope toward the far end of that main.

Jamie Hall

Not just Dunham

there were several other types of systems -- my Hoffman equipped system, for example, which had "crossover" traps at the ends of the steam mains, linking to the dry returns.  They did this instead of having main vents at the ends of the mains.  In the Hoffman equipped system, for one (and several others) this was partly because they only wanted one main vent together with some other controls, all located at the boiler.  The crossover traps were just like radiator traps, or sometimes one size larger.



You could either put those back in, or put main vents out there...

MadisonMatt

I was wondering

Thanks Rod and Jamie.



Suspect what Jamie said, is that there were some cross-over traps or something at the ends of the mains that connected to the wet returns, given there proximity, to one another.  I believe that setup though would require an air separator near the boiler?  I will check on the pitch of the steam mains just to be sure. 

I don't get any water hammer or anything like that, not sure if that matters.

I am also pretty sure that my thermostatic traps are toast.  Most of them look original, (unless the caps never change and the kits are only the interior of the trap).  I also think I used my infra red thermometer and didn't see much temp difference.

Thanks guys, very helpful stuff.

Matt

Jamie Hall

If it were mine...

I'd reinstall the crossover traps and put in a good bit of main venting ("air eliminator"?) at the boiler -- but I'm a bit of a nut about restoring the original!  The lack of hammer and the fact that it works as well as it does suggests that all the mains and dry returns pitch back to the boiler -- although I'd be inclined to check that, as things do settle.



Replacement trap kits just do the innards -- so you wouldn't see a change in the covers (you might, however, see wrench marks on the caps, if someone used a pipe wrench to undo them!).  The infrared thermometer is a pretty good guide, though -- although it can be a little tricky to get a really good reading sometimes.  A lot depends on how much difference is not much.  If the pipe beyond the trap is more than 10 F cooler than the pipe going in, my feeling is that the trap is probably still working... less difference than that is perhaps iffish.  Only one or two degrees is not good.

Dave in QCA

counterflow 2 pipe not common

I agree with Rod that this is certainly uncommon.  However, we all know that one pipe systems were sometimes installed a counterflow piping setup.  In one pipe, the steam mains were obviously carrying both the steam and condensate.  Although I have not come accross a counterlow setup in a 2 pipe system, it stand to reason that it would certainly work.  When you consider that the only condensate in the steam main would be what actually condenses in the mains and risors, a counterlow set up would probably work better in 2 pipe systems than it does on 1 pipe.

Just my 2 cents on this.

MadisonMatt

What to do?

Well,

I do wonder how well my system is working.  My highest gas bill last year was $380 and not a very cold winter by recent Wisconsin standards.  That seems pretty high to me, but I just got out of heating oil, which was terribly expensive.  I remember struggling with the infrared thermometer some last year.  Also, the upstairs is cold, hoping to insulate the attic this year.  So not sure how aggressively to tackle this.  I did check the steam mains and I am pretty certain the pitch back to the boiler, but I couldn't find my level to confirm.



Any other thoughts?  Should I do more evaluation to evaluate how quickly things heat up, etc?



Thanks,

Matt

Steamhead

I wonder if

that system was bigger when it was first built? That would explain those plugged tees at the ends of the mains. What's on the other side of the walls where the mains now end?



Also- many Tudor systems were run counterflow, but it's uncommon on other Vapor systems. This system has a history begging to be uncovered.



I was just in Milwaukee several weeks ago- wish you had posted this sooner!

Rod

Parts

Hi Matt-

Picture #1 - If pipes marked H & G are drips, they should not join until they are in the wet return below the boiler water line. As they are now they "cross flow" and interfere with each other. Each line will also need its own main vent.



Radiator traps- I have an air impact wrench and have found that it works great for opening old traps. Now use it more on old traps than on my car which is what I originally bought it for.

Here's some sources for complete traps & parts:

State Supply

http://www.statesupply.com/steamTraps.jsp



Rebuild parts for Steam Traps (Thermostatic,  F&T)

Barnes & Jones

http://www.barnesandjones.com/



Tunstall

http://www.tunstall-inc.com/tunstallsteam.html



When using an infrared thermometer (at least on the one I have) I found that you have to hold it close to the spot you want to measure as the farther you are away from the heat source the larger the area that is sampled.  When I took a reading a few feet back,even though I had the red dot on the outlet pipe from the trap I finally figured out I was taking in the trap body's temperature too. Moving closer shrunk the sample area and I got more accurate readings.

Jamie's suggested approach is a good one and besides restoring the system more towards its original form, may also be the easiest to reconfigure.as the ends of the mains are in close proximity.  The slope of the main back towards the boiler is rather odd. One can only wonder how they got that way.

- Rod

MadisonMatt

Sorry

Sorry, Steamhead, I wasn't thinking about my system until now (getting cold).  I would have been happy to pick you up though and show you around MadTown.



Also thanks to Dave (missed your post earlier) and Rod.



The mains end at an exterior wall and I know that nothing used to be there (we have a sister house that is identical in the area). 



I suspect there were crossovers at one time and that they went bad and then were removed and the mains pitched back.  Is that realistic?  Though it sound repairing the cross-overs would have been straightforward. 





I wonder if I should get the drips sorted out as mentioned.  Should I look at getting vents on the end of the steam mains in order to help things along, considering the air from the mains has to get all the way up to the rads and then into the returns and out my single main vent?   Also, I hear whistling at the main vent when the steam is up, and my understanding is that indicates inadequate venting.  Lastly, I have been reading on the Wall and Dan's books, but struggle to know what is normal for my system.  I am beginning to think that if I have to ask then things are going right.  Is there a rule of thumb as to how quickly the rads should heat up or the mains after starting a heating cycle?



Thanks again all, you folks are a wealth of knowledge and I am enjoying my little bit of detective work with your help.



Matt

JStar

In the lettered picture.

The pipe marked H looks pretty high to be a return. Are you sure that it is? Where does it go outside of the picture? Does it drop into the top at the end of the steam main? That could be your venting crossover.

Dave in QCA

Main Returns = Condensate Returns

• Rod, I think that when he labelled H & G as Main Returns, he meant that they are the Return Mains, i.e., the dry condensate return mains.  There should be no steam there and therefore, steam crossflow is not a concern.  As Jamie has said, the vent needs to be super capacity, because it is venting everything in the entire system.  The end of the main venting can be done with a Thermostatic Trap at the end of each steam main that would discharge to the plugged condensate line, as it apparently was when the system was built.

MadisonMatt

More

Thanks all.

H & G are indeed return mains.  Dave your post came up after I posted mine again.  The two return mains run along the basement ceiling in parallel to the steam mains, picking up all the returns from the rads supplied by that respective steam main. 

Given that my steam mains pitch towards the boiler would putting crossover traps at the ends of the steam mains be the same as putting vents at the ends of the mains as far as letting the air get out the way? 

I suppose no matter what, I should add more venting back at the main vent by the boiler.  How do you estimate the amount of venting needed?  As previously stated, I am venting my entire system through that one vent.

I will probably be able to get more data once I turn on my system in a few weeks.

I was going to have a heating contractor come out and look at things as I think I need to have my boiler skimmed/flushed.  But, I also wanted to address some of the concerns that I am mentioning to you all, but wanted to be sure I didn't get a knucklehead as Dan says.

Thanks all, and please keep the questions/suggestions coming.

Matt

Jamie Hall

Aren't you having fun!

Yes, putting the crossover traps back would have exactly the same effect as putting vents of the same capacity on the ends of the steam mains -- provided that there was adequate venting capacity at the boiler.  Which there probably isn't.  I don't have the guides for vent capacity handy at the moment -- someone else will, hopefully, put up the link for you.  It depends on the size and length of the steam mains.  And adequate vent capacity will help the system heat faster -- and more evenly.



I might add in passing that adequate vent capacity was much less of an issue with coal fired boilers, as they built up to full steam production much more slowly than an oil or gas fired boiler does -- and hence needed much less vent capacity.  Typically nowadays we wind up with two or more large vents -- such as Gorton #2s -- at the boiler to handle things.



And yes, you should get any drips sorted out -- they're important.  The general rule is that any low point in a steam main or dry return should have a drip to a wet return, to allow any condensate which forms to get out of the way of the steam or the air.  To which I might add that the low point should be deliberate!  If it is just a sag from age (all too common) then the sag should be eliminated by adjusting the hangers.  That said, if both the mains and returns pitch back to the boiler, then additional drips aren't needed.

Rod

Separate Drips

Hi Dave-  I understand what you're saying. I just think that dripping both return lines individually into the wet return has a lot of benefits. It would make each set of steam and return mains independent of each other. Separate venting, separate return, then if a trap blows out it doesn't affect the whole system. Being split into separate independent sets would also assist trouble shooting.  As you said the system needs more venting and therefore each main set having their own vent, they wouldn't "compete" for the one vent..

Piping wise an easy change to make with a large potential benefit. Just my 2 cents

- Rod

A caveat to Matt - I'm a home owner and probably the most inexperienced of those replying to you so please keep that in mind when you are reading these replys and there is a difference of opinion.

Dave in QCA

Points well taken

Rod, you are indeed correct.  The benefits you state would certainly be gained with separate drops.  Who knows, it may have been that way originally.  And as you say, it would be an easy change.

Disclosure time....   I am not in the trades either.  I did work as a maintenance mechanic, and maintenance department manager in a hospital complex that had 2,  238HP high pressure Kewanee scotch marine boilers.  I gained a good deal of experience maintaining the various steam apparatus that operated in that system.  However, low pressure and vapor systems are a different animal, and I'm totally indebted to this site, the folks who participate, and Dan's books for helping me gain some understanding of all of the subtle intricacies of how these great machines work!  Without it, I confess, I would have probably been in the "turn up the pressure" knucklehead group! 

Rod, My hat's off to you for the thorough and well stated answers that you post; amazing knowledge for one who is not in the trades. 

The Steam Whisperer (Formerly Boilerpro)

My thoughts

Now that we have an idea which pipes are what a better picture is emerging.

It looks like your near boiler piping is good (looks like the Dunkirks I used to install), so consider yourself lucky. Pipes are also insulated, also very good.  It is unusual to have a two pipe steam main to be counterflow, but there is certainly nothing wrong with it and it probably creates a lot more headroom in the basement. 

If the steam mains can be vented with typical one pipe steam vents, I would do it this way.  This way you can give each main the appropriate amount of venting to have them heat evenly.  Combined with this, I would leave the the current vent for the return mains small.   This creates a little more restriction on the radiator venting and helps direct the steam down the mains on warm up.  The old saying goes"Vent mains quickly and radiators slowly, but completely"  Once steam gets to the end of the mains the main vents close, pressure builds a little and starts filling the radiators.  The venting needs drop quickly because the radiators are now condensing a lot of steam, so little air needs to be vented. 

After getting main vents on, I would see how the system heats.  It will probably improve the steam distribution dramatically and start heating the second floor.

Also, it sound like your traps may be bad, so this could also be giving you troubles, especially if your radiators usually heat all the way across.  Instead of rebuilding traps, I would suggest upgrading the system to orifice in the supply valves.  With this technique, you can meter the amount of heat needed to each room (based on current heat load calculations) right at the supply valve. So long as you control peak pressure and the radiators are oversized, steam will not get to the traps, so they will no longer be needed.  Systems set up this way heat very evenly, since steam is greatly limited by the orifices during warm up, forcing it down the main, and then a little pressure builds and all the radiators being heating at once, with the orifices proportioning the heating of each room according to the heat loss.   This typically will allow the use of a much smaller boiler when it comes to replace the current unit, saving replacement costs and fuel.  A modulating input boiler should also be a good fit for the system after the orifices are in place, probably cutting fuel usage another 12% or so.

MadisonMatt

Consensus?

I can't believe all the great posts in response to my questions.  Thanks, Steampro the insulation job so far is my first stab at it.



I did check the pitch of the steam mains and they do pitch back to the boiler. 



Therefore the consensus appears to be to vent the mains, the only question I have is do I have to worry on my counter-flow, 2 pipe system that venting the mains will increase the steam velocity enough to carry condensate up with it causing water hammer of some other such problem in the steam mains?  My guess is the pipes may be undersized for a counterflow but have no idea.  Currently don't have water hammer, and  I don't want to make things worse.



As to the dry returns meeting together rather than going separately into the condensate drip and then wet return, may or may not be much of an issue.



As to the main vent at the dry return (Hoffman 75 by the looks of it), maybe wait and see the effects of vents on the steam mains?



Lastly, what size vents do I use?  The consensus on The Wall, is Gorton #2 seems to be the large vent of choice.  But, how do you select a size, measure the volume inside the main?  I have The Lost Art, but it doesn't appear to have an appropriate table in it.  Web search and searching here were a bust.



So I am considering trialing some steam main vents only at first and then considering separate drips for the dry return mains and increased venting of the returns in a stepwise fashion.



PS:  Steampro yer blowing my mind with the orifice thing, kept me up reading about it.



Matt

The Steam Whisperer (Formerly Boilerpro)

Vents, orifices, et el

For vent sizing, Get the e Mail booklet called "Balancing Steam Systems" under the shop tab......its a throughly researched and fantastic source from some of the best in the business  Steve Pajek and Gerry Gill.

Orifice systems are nothing new, alot of the vapor systems from the 20's used them.  Tunstall sells them and may be able to give you direction.  Also Google Frank Gifford.   I also have some articles I've written  about how they fit into the larger scheme of things that I hope to get published in the next year. 

MadisonMatt

Last thoughts?

You all have been a great help.



Any thoughts on my final concerns listed in my prior post?  I have a feeling that it will be a try it and see. 



Lastly, Steampro I read last night, that orifices can be tricky to size, and the orifice can degrade over time and become larger, allowing steam to get in to the returns, and my thought is this could be harder to detect than failure of the thermostatic traps?



Thanks again for all the great info.  If anyone likes I can post a reply detailing the results when I get things done.



Matt

MadisonMatt

Orifice

Steampro,

Thanks for the links, I was reading about condensate orifices and they don't sound appropriate for residential steam.



I think you meant Henry Gifford and not Frank.



I will look into the tunstall combined TRV with orifice when the time comes.



Matt

The Steam Whisperer (Formerly Boilerpro)

Orifices....

Yes, I'd steer clear of the condensate orfices, however, supply orifces are another story.