Steam Header

ottawan

On page 51 of the "Lost Art" I have noticed a picture of a header hookup with the caption "Never do this!". Well it's exactly what my installer did 15 years ago! (see photo). My system is perfectly silent for the first week or so of the heating season and then I start getting banging in the line leading up to the third floor (see photo). Could the header piping be related to the noise? (I can't remember if there was the same banging with the old boiler - that was a long time ago and I was living on the first floor when the boiler was changed).



If this is a problem do I dare ask the contractor to re-pipe the furnace after all these years? What would be a fair arrangement? (I can see in the manual that comes with the furnace that they have the correct piping clearly shown)

Dave in QCA

copper added?

It looks like one of the copper lines that we see are connected to the steam piping.  Is that the case?

Rod

Piping Problems

Hi- You are right in thinking that your header is piped incorrectly (Page 51) However since you have been living with it 15 years I would think you

would have a hard time arguing the point with the original contractor. (He, I'm sure, thinks it was done properly)

 As it is now piped the steam streams entering the header oppose each other on their way to the riser going to the mains. This collision causes wet steam which is then carried up into the steam mains.  As to whether you have it corrected would depend on how soon you plan to replace you  present boiler. It maybe better to just wait until then.



There are also other pipe configurations in the system that maybe causing problems. (see picture 03) It would seem that from where the riser pipe from the header joins the main(s), the mains are pitched uphill so that condensate would run back down and would collect in the low point and after accumulating, would interfere with the steam flow. This could be corrected by installing a drip as in done in counterflow mains but again might be something to be considered when you put in a new boiler.



On the piping going to the third floor (see picture 04)  "A" is the steam main, "B" is the riser going up to the third floor (?)  What are "C" and "D" and where do they lead?



You mentioned that your system is quiet for the first week or so then the noise starts. This is probably due to the fact that during this time water has been able to pool in the system and now causes water hammer ("the noise"). It may have not happened on your old boiler as on the old units steam passed more slowly through the system and this allowed trapped water to escape. Let us know what the letters are in Picture 04 and maybe we can figure out what is happening.

- Rod

ottawan

explanation of photo

Dave - there is no copper in the picture - what you are seeing is cast iron with a bit of surface rust (resolution not helped by my lousy camera)



Rob



Your comments on the re-piping are very sensible. It won't kill me to wait till a new furnace is needed (It will be a race between me and the furnace as to who goes first!). As for the mystery points in your blowup of my photo (nice job - did you use "Paint" for that?). Here are the answers as best I can make out:



"C" is a Gorton air release valve like on a steam radiator. Both of these lines ("B" and the line to which the valve at "C" is attached) rise to the third floor. I can see them going up through the second floor and on up into the ceiling to the third floor. From the hole in the2nd floor ceiling it appears that the line "C" takes a turn to the south (there is definitely an elbow there) towards a bedroom where there is one rad which heats up very nicely (although we almost always keep it shut off). I can only assume (can't really see) that "B" turns North and feeds rads in each of three bedrooms which also heat up pretty well. These rads are also normally turned off as we don't use these rooms much anymore (kids gone). It seems strange to me that the two risers get very hot right up to the third floor even though all the rads that they feed are closed. I wonder if the valve at "C" explains this  (or perhaps there is some kind of loop that the steam is circulating in) - I have never understood why the valve is there in the first place. It might help to know that the house dates to 1883 and I'm pretty sure the steam was added later and there were several additions to the house - though not in my tenure.



Thanks for taking the trouble to make  your post so clear. By the way, the "D" is just a copper water pipe going up the same route to the third floor - it gets pretty hot in the winter!.

ottawan

Apology

How could I get the name wrong. Sorry about that Rod.

Rod

Steam System

Thanks for your answers. Seems like rather a odd place for a Gorton Valve.

 At what pressure is the system operating? It should be operating at under 2 PSI Max or lower.  (Lower = better as more pressure = more fuel!) I've been assuming that this is a one pipe system and the following applies to a 1 pipe system.

On shutting off radiators - Just closing the valve sometimes doesn't shut off the radiator. Old valves leak, which allows some steam in enter the radiator, this condenses and over time fills the radiator with water as the steam coming in through the small crack doesn't allow the water to escape. A better way to shut off the radiator is to turn the air vent on the radiator, up side down (180 degrees) so  the "bullet" shape is pointed downward. This shuts the vent and the shut vent doesn't allow air to escape from the radiator. If the air can't escape, steam can't enter the radiator. Leaving the radiator inlet valve open makes sure any condensate drains.

 You might also want to take a look at TRVs (Thermostatic Radiator Valves= Page 96-97 in "The Lost Art...")  My house is in Maine and I shut down a lot of the rooms in winter using TRVs. The minimum setting on a TRV is about 42 degrees F which keeps the rooms just above freezing so the pipes in the wall don't freeze. 



As for boiler replacement. Are you now using gas or oil?  Modern steam boilers have improved and are getting much more efficient and will be more so in the next few years so depending on your fuel usage it may be beneficial to think about replacement in the next couple of years one way or another.

For photo enhancement I use Corel Paint Shop Pro. It's great for touching up photos and doing simple diagrams.

- Rod (aka Rob

Dave in QCA

Riser vent in Basement

Rod, I think what is going on here can be explained by the following.  No way to be sure without examining the system in person, but here goes.

Pipe A is end of main or major lateral that  slopes away from the boiler, so, it has to have a drip leg, which it does, and it drops to a wet return.  Pipe B is the steam riser to the third floor.  3rd floor radiators can be problematic in getting steam to arrive at the same time as the rest of the house and it looks like the dead man dealt with that issue rather well.  (Note that Ottawan indicates that the third floor heats very well when when the radiators are turned on.)  Instead of installing a main vent at the top of the riser, they have brought a return back down to the basement.  I would bet that the lateral on the third floor is sloped away from the riser and that the condensate from all radiators connected to it flows back down pipe C.  The entire riser, 3rd floor lateral and drip leg are vented through the Gorton main vent at pipe C.  Rather ingenious, and not at all what we are used to looking at.

So now, why is this thing banging?  Ottawan, are you sure that both valves in the drip legs are open?  If the valve in the drip leg under pipe B were closed, it could cause a whole lot of hammering once the pressure was great enough to push steam through the water dam.

Regarding shutting off your radiators, as Rod says, old valves often leak.  Many times it is because the washer disk is completely gone and you're simply turning a metal plate on the end of the valve stem against the seat.  However, if the valve is shutting off, and you're not collecting a reservoir of water in the radiator, you should be fine.  The valve washer may be intact.  Rod's alternate method of turning off a radiator, or for regulating it at a low set temp are excellent ideas.

ottawan

Drip Line Valve

Dave







I think your explanation is promising. If I understand it correctly it

seems to me that nothing would prevent the steam from circulating up the

riser (B) and then down the dedicated condensate tube (C) even if all

the rads were shut off. That would explain why both pipes get hot even

when the rads are shut off - or am I missing something?







The two valves on B and C are both turned on. But I wonder if there

might be another explanation. Those pipes have been there a long time

(at least 50 years and probably longer) and B is connected into C near

the basement floor with a 90 degree elbow. I suspect that if we

dismantled that elbow we would find a big build-up of solids which the

condensate would only be able to get through very slowly. I just

replaced the return pipe from B and C which runs along the basement

floor and then back to the boiler - it was completely rotted out and

leaking but I didn't think to replace above it up to the level of the main. Could this be the problem?

Dave in QCA

blockage or some sort...

Regarding your paragraph 1, yes that is exactly was I was trying to say.  Keep in mind, it is possible that I am not correct.

An accumulation of debris and blockage where where B is connected into C is also a suspect.  I would also check on the valve on the drip leg of the steam main.  I have only seen it once, but I have indeed seen an old gate valve fail, and the only way it was finally discovered was by taking the valve out and looking at it.  The handle would turn a normal amount of turns in either direction.  It acted like you were opening and closing the valve, but the gate was stuck tight in the closed position.  If you separate the union just below the valve, you should be able to visually check it out.

ottawan

Gate Valve

Dave



Thanks for the tip on the gate valve. I'm not sure I can move that union after it's been sitting there for all those years but I'll give it a try. I suppose if I can get it off I could also check for residue in the other direction.