Near Boiler Piping

SteamsGreat

I recently had a heating professional look at the steam system piping in my house to help with a really loud water hammer problem that I have leading to one of my radiators.  I suggested that since the water hammering occurs at the start of the heating cycle, I thought the first step to correcting the water hammering was to insulate the piping.  He suggested that I should start with correcting my near boiler piping because it was allowing steam to go up by return lines.  Having thoroughly read We Got Steam Heat, I thought that the piping around by boiler is pretty close to correct except for the piping for the header.  Is the piping around the boiler incorrect enough to cause a water hammer issue?  If it is wrong, how should it be?  I would like to know to check it against what the heating professional suggests.  I have attached several pictures and a diagram of my steam piping.  Any help would be greatly appreciated.

JStar

?

The problem radiator has two pipes? I bet water is sitting at the end of that main. I would change that radiator to one pipe, and connect the end of the main into the return. But it all depends on certain heights and pitches.

crash2009

In some ways

your boiler is piped the way mine was.  I am not a steam professional, just a homeowner that became interested in steam after I found out I had a problem.  I am curious to see how this one unfolds.  Do you mind if I observe?  In your diagram the radiator on the top left, Does it have 2 pipes and all the rest just 1 ?

crash2009

This is how

they fixed mine.  It works great now.   I have a tendancy for overkill.  There must be an easier way.

clammy

near boiler piping?

Your steam risers out of the boiler and supply side piping is not even close to be correct and i see that your dry returns are tied together way above the water line and the main vent is in the wrong location .the return lines need to be seperated  and drop down seperatly and tied in well below the hartford loop  (12  inches),and a vent should be added to each dry return.On another note the pressuretrol should be checked to see if it is set correctly (1/2 cut in 1 cut out)and that the pigtail is not clogged .Insulating the piping would also quite down the hammer if not it would put more heat in your rads and lower your fuel usuage and help pervent future condensate grooving in your steam mains whih lead to leaks at fittings in your steam supply mains .The boiler looks like it,s about 30 years old when was the last time the water side of the boiler was cleaned or the boiler servied and maintained .thrying not to be hard peace and good luck clammy

Long Beach Ed

As always...

Clammy has the answers. 



What is causing your water hammer is the return on that two pipe radiator.  It should dip below the water line instead of joining with another steam-carrying pipe.  Since both the supply and return are filled with steam, how can the condensate return? 



As Clammy says, the rest of the system can use help also.  But if you don't want to invest, now just dip that return down below the waterline as illustrated in the sketch above. 



But beware, around these parts a day's work with threaded pipe runs some big bucks. 

JStar

And...

...not only bring the radiator return lower than water level, but drip the end of that main, too. If the radiator has a trap, the return and main will need to be water sealed separately. Converting the radiator to one pipe would limit the amount of repiping.

clammy

futher looking

After another closer look at your diagram that last rad is piped wrong and should be repied to a single pipe and the supplymain ran out and tied into the dry return be sure  when the supply is reduced a concetric reduicing fitting is used so condensate does not pool in the main which will cause more water hammer then you have already the rest of the suggestions will vastly improve your systems performance.I feel that is where your water hammer is coming from not so much as steam heading up the return but that condensate is pooling in the area and annot drain properly  peace and good luck clammy

crash2009

You guys are ferocious.

Water hammer no more.  Main vent, drop the return, and tie it in below the Hartford.  I wish we had a picture of the 2 pipe radiator. 

SteamsGreat

Near Boiler Piping Followup

Thanks for all the great replies to my question, but before I gear up to have this work done, I was hoping to clarify everything I have learned and ask a couple of followup questions.  I also thought I should add that the water hammering is worse the colder it is outside.



It seems like there are two issues I should correct.  First to correct the return lines nears the boiler by splitting them, adding vents, and dropping them lower than the water line; second to convert the end radiator from two pipe to one pipe and return from the end of the supply.  I redrew my diagram to show the needed changes.  Any feedback if I have something drawn incorrectly would again be appreciated, especially regarding the return at the last radiator.



To respond to clammy's first reply, I have the pressuretrol at 1/2 cut in and 1 cut out, but I made that change this summer; it was set to 1/2 cut in a 2 cut out previously.  The pigtail is new from last heating season, though I think it needs to be turned 90 degrees (do others agree?).  I have the boiler serviced each year (thoroughly cleaned, burners removed and cleaned, etc.), but I am not sure if the water side of the boiler was cleaned.



JStar and clammy, I did not quite understand your second replies, I drew in the diagram what I thought you were implying about the last radiator, but if you could clarify if I have it wrong, that would be really helpful.



Other than adding the two vents at the return, should I have any other vents added?  I will post a picture of this two pipe base board radiator tomorrow.  Unfortunately, the

last length of piping to that radiator is in a crawl space I do not currently have access

to so I will not be able to see the piping just below the radiaor; not to mention that work on that radiator will have to wait a short while.  I can have the near piping changes made now and add the insulation.  Thanks again for all of the great information.

crash2009

If

you are proposing to do all that, you may want to make sure the boiler is OK.  I am not sure how to go about that.  All we did at my place was flood it and check for leaks.  I was assured from the previous homeowner that mine was 6 years old.  Also you may need more main venting.  I would thoroughly investigate that crawl space area before I did anything.  You never know what you are going to find in there. 

JStar

Minor details?

I would try to run the steam main past the last radiator before dropping down at all. Refer to crash's drawing.



You should also find the EDR rating for the radiator that you are converting, and match up the capacity of the current supply pipe. You may need to upgrade to a larger size. Maybe not, but it's worth finding out. If you can get pictures with measurements of the radiator, the supply pipe size, and how far the supply runs out before going up into the floor, we can figure that all out for you.

The Steam Whisperer (Formerly Boilerpro)

Baseboard Radiator??????

If that two pipe radiator is a baseboard radiator, piping it as a one pipe is probably a bad idea, since the supply tapping is too small.  Leave is piped as a two pipe with the baseboard sloped to the outlet (away from the supply) , then pipe the outlet below the water line like the returns off the one pipe mains.

SteamsGreat

Two-Pipe Baseboard Radiator

Here are some pictures of the troublesome two pipe radiator.  My plan is to leave it as a two pipe radiator until I renovate the kitchen it is in, at which point I think I will switch it t0 a more standard one pipe radiator.  JStar, I can provide the radiator's measurements and supply pipe size and run tomorrow.  Thanks.

Long Beach Ed

Fine...

It should work fine if piped as BoilerPro described. 

crash2009

I wonder

if that baseboard radiator vent is working, isn't that a quick vent?  Has some paint on it.  Is it painted shut?

JStar

Agreed.

Keep the baseboard two-pipe. Extend the return from that radiator below water level. AND bring the end of the main steam line down below water level on its own. You can join the two after they are low enough to form a water seal. Wouldn't be a bad idea to add a main line vent at the end of the main, too.

SteamsGreat

Two-Pipe Radiator Size

That two pipe radiator is 66" long, 2 1/8" deep, and 8 1/2" high.  The heating element inside is approximately 6" tall.  The supply pipe from the boiler to the first radiator is 84" and is a 2" pipe.  At the first radiator it reduces down to a 1 1/2" pipe for the last 292".  The return pipe is 3/4" pipe.  JStar- I am a confused by what you mean when you say bring the end of the main steam line down below the water level on its own and join the two after they are low enough to form a water seal.



A second question I have is in regards to the boiler itself.  It is an American Standard gas boiler (150000 Input / 120000 Output) Boiler # G-26; Series # 6BSE-J5.  I have been told the boiler is about 30-40 years old and due to the quality of the time period when it was manufacturer the boiler should last another 30-40 years; and since boiler effeciency for creating steam has not improved that much it probably is not worth replacing.  On the other hand, I have been told that newer boilers are quite a bit more efficient and that I might should consider replacing the boiler.  I ask, because I do not want to re-pipe the near boiler piping only to do it all over again in a few years if I replace the boiler.



Thanks

Long Beach Ed

Modern Boiler

My opinion, and just my opinion -- there will be others -- is that the boiler is of a modern design and if it is properly sized and in good condition, little will be gained from replacing it... unless it is over-sized, which most are... but... 



Problems come in when re-piping an old boiler, however.  If you do it yourself, the cost of piping is high but substantially less than if you employ a steamfitter to do the job.  The majority of the labor cost of a new installation is in fitting the near boiler piping. So why waste it on an old boiler, where for a few bucks more you can replace the thing?   Otherwise your costs will be spread out only over the relatively short  remaining life of the old unit instead over perhaps three times as many years. 



The other problems are taking the old stuff apart and the chance that you may damage the old boiler.  Most plumbers will not guarantee that the old unit will survive the rigors of replacing piping.   They'll be lots of jarring around, stressing and banging. You may wind up with new leaks or problems.



Then you must look at the overall condition of the old girl.  Honestly.  Are there any leaks, any bad rust, are the controls less than 15 years old?  



Hasn't it earned it's retirement, as McDonnell Miller used to say?



Usually, if you are going to pay the extensive labor charges involved with re-piping, the most cost efficient route is replacement. 



Easy for me to say -- it isn't my money. 

JStar

To clarify...

If you look at your drawing, the steam main on the left ends by going right up to that last baseboard radiator, right? So, the condensate has nowhere to go. It'll back up against that last fitting, causing water hammer and weaker steam on that main. Just picture water in that main. How is it going to get back to the boiler? You don't want it going backwards. So, you need to have the end of the main piped back to a wet return.

Steamhead

To give you an idea

of how old that boiler is...... the American-Standard boiler line was sold to Burnham around 1971. So it can't be any newer than that. And in those days, there was no incentive to build efficient equipment. The only thing that mattered was getting the price as low as possible.



Some of those old A-S gas boilers had frighteningly high stack temperatures, even if they weren't over-fired. Even a cheap (and I don't mean that in a nice way) atmospheric gas replacement boiler would do better than that. So whoever told you they haven't gotten more efficient is dead wrong.



The most efficient residential gas-fired steamers out there today are the Smith G-8 and Slant/Fin Intrepid models. These are mostly sold as oil-fired units but are approved for use with power gas burners, and offer better thermal efficiency than the usual atmospheric types.



Here's a pic of a Smith G-8 and an Intrepid we installed.

The Steam Whisperer (Formerly Boilerpro)

Actually, STeamhead.....

you'd be surprised how efficiently those G boilers fire.  I had a hot water model in my home and that same150,000 btu steam fired model in a neighbors home.  They are probably from about 1962.  If i remember right the combustion tests came out at about 35% Excess air and a calculated efficiency of about 78% on the steamer.  The heat exchangers were heavily pinned, so long as  the pins haven't eroded off (my boiler was running cold for 30years), firing efficiency is  nearly as good as a cheap atmospheric today.   Basically that same boiler is still made today, with some efficiency improvements,  as the Burnham Independence model, probably the best smaller atmospheric steamer today.

That said, installing a new Slantfin Intrepid with a gas burner (maybe even a modulating gas burner for another 12 to 15% fuel savings) would still be much more efficient, since it is better than any other gas fired smaller model on the market.

Steamhead

Well

they may have lost some pins, cause I've seen them over 600° in the collector just prior to the draft hood. At that point I recommend replacement. The Independence does much better but not as well as a G8 or intrepid

The Steam Whisperer (Formerly Boilerpro)

Low O2

With the excess air so low compared to most new atmospheric boilers (typically 50 to 60% excess air versus 30 to 35% on older units), the stack temps tend to run higher on the older units.  I wish they would tighten up the air on newer units to pick up a couple pionts of efficiency, but for some reason they don't.  I guess it is to help make the boiler more Knuckhead proof and still allow it to run safely.

SteamsGreat

Thanks

Just wanted to thank everyone who replied to the thread for all of their help and insight.

crash2009

Problem radiator?

Y'know, I was reading something that may apply to your problem radiator last night.  I scanned it for you and highlighted it in red.  I scanned it from page 3 of EDR by Dan Holohan.  As I declared before, I am no expert on this stuff but, this paragraph reminded me of your thread.  Is this one of those radiators that have a "Something" inside it that has stopped working, and is now causing all this water hammer?  If you look at the picture of "the problem radiator" on the top, on the left, is that a vent, a trap, or could it be related to the water hammer problem?