Dry Return piping

USA498

I have a single pipe steam system with two loops in the basment. The dry returns are connected together above the waterline before dropping down. Should they drop down seperately below the waterline before connecting to the hartford loop ? Also, I don't think the installer piped the hartford loop properly. 

Rod

Boiler Piping

Hi - Your boiler piping, as you suspect, appears a bit "screwy" and in need of being redone.

Could you provide us with some more pictures? Take them from different angles around the boiler and farther back to get the boiler and piping in the picture  so we can trace the connecting piping to see how/to where it is connected.

If we need detail, we can blow the pictures up.  What is your boiler make and model? There should be a nameplate on the boiler that gives this information. You also might want to look at this video of Dan's which explains the configuration of near boiler piping.

http://www.heatinghelp.com/article/107/Steam-Heating/118/Steam-boiler-near-boiler-piping

- Rod

 

Jamie Hall

There's no harm

to connecting the dry returns together before they drop -- in fact, most two pipe vapour systems do just that.



This assumes, though, that you aren't getting steam into any of the dry returns!

Dave in QCA

Dry Return Terminology is Confusing

Jamie,  I've been inactive for a while.   But I was just reading the current posts, and have to jump in on this one.



This is a one pipe system.  The dry returns, therefore, are the end of mains that have circled around the basement, back to the boiler, where they would have a main vent, and then drop down and connect via a hartford loop.  In this type of set up, they should remain separate until they are well below the water line.  This prevents steam cross over from occuring, which can interfere with venting on the slower loop.



I wish we had a different terms for a dry return on a one pipe, and the dry returns on the return piping of a 2 pipe system.



In my system, I have both types of dry returns in my boiler room, because the steam main circles all the way around and back to the boiler room.  It doesn't drop until it gets to the boiler.  Of course, I also have the dry returns on the "condensate" return piping.



And Jamie, I know that you already know everything I have just stated.  You're one of the brighter bulbs in this room.  The terminology makes it easy to miss.



D

USA498

New Photo's

Here are some photo's at different angles. I think I should have the two returns dropped to the level of the mud leg and make a proper hartford loop. The boiler is a Peerless  JOTTW-175-S with 10 radiators. Many thanks for your help.

Dave in QCA

The Manual Says

You boiler should have 2 - 2" risers coming out of the boiler.  The header should be at least 2 1/2", and the equalizer should be 1 1/2".  These are minimum sizes.

Copper should never be used for steam piping.  Also, the diagram indicates swing joints for the risers and this is an important detail.

And you are right, the 2 dry returns, since they are indeed steam mains, should not connect until well beneath the water line.



One could say that the piping is pretty much all wrong.

Here is the link to the installation and operation manual.     http://peerlessboilers.com/DesktopModules/Bring2mind/DMX/Download.aspx?EntryId=89&PortalId=0&DownloadMethod=attachment

Jamie Hall

Right you are...

Dave -- that's what I get for a) being well and truly biased in my thinking towards two pipe and particularly vacuum systems and b) not reading the post as well as I should have.



Oh well.  Where's another cup of coffee?

USA498

Keep Current Header ?

Dave Thanks for the boiler manual. Do you think I should keep the very old 4" header or replace it with 2 1/2" when I have the copper replaced ? My initial thought was to replace the copper with a nice 2 1/2 " drop header and pipe it to the old 4" section.

Steamhead

That would work well

We've done this too. It will slow the steam down to about where it was with the old boiler your JOT replaced. Be sure to insulate it well, or you'll lose a lot of heat from all that surface area.



Here's a shot of one we did. It's a Weil-McLain SGO-9 with a 3-inch drop header, on a Kriebel system. It replaced the original coal-converted boiler, and we piped the 3-inch header takeoff into the original 5-inch header. This system is getting incredibly dry steam, and heats up very quickly!

RDSTEAM

this install is quite interesting

the fact that he is using a vaporstat is quite impressive.  His venting looks to be in tip top shape as well.  Then on the other hand his near-boiler piping is poor and his "hartford loop" is non-existent. makes me wonder.....if you know enough to vent the mains properly, assuming those gortons are enough, and throw on a vaporstat to give you nice low pressure, you should know enough to NEVER have your near-boiler piping look like THAT.

USA498

I like to tinker with things

I have been scouring this site for a couple of years and any of the correct stuff you see I have  done based on info from the Wall. Everything else came with the house.

I checked the Large ( OLD ) header height and based on the middle of the sight glass I get 23" to the bottom of the header. Is this A dimension going to cause problems ? Also, I have to diagram the drop header for my plumber, when should I switch to 2 1/2 " ? I thought after the drop when it goes horizontal. Is it OK to use a street ell and a 90 elbow for the piping before the drop ? Many thanks for your replies !

RDSTEAM

"a" dimension

is not where the 24" for header height comes from. that 24" is just to try and dry the steam out as it leaves the boiler. Its actually better to go 24" off the top of the jacket if you have the room. Also, where the copper goes to black, if that header is pitched toward the boiler riser you are going to end up with a water pocket there and that equals problems.  Your "a" dimension is from your water line to the bottom of your lowest horizontal steam carrying pipe. Residential can be 18" but more than likely its closer to 28", this allows the condensate to stack up and add to the leftover steam pressure and push the return water back into the boiler. i wonder if those dry returns were always there or if there used to be leaky wet returns that were abandoned hmmm.... CORRECT THAT NEAR BOILER PIPING

Charlie from wmass

If you need to diagram for your plumber

maybe you need a new one? To answer are street 90's ok sure they are but if you use a drop header you need to make sure the condensate does not pool in the header. The 21/2" is for the horizontal piping that connects the risers and the feed header. So part of it you have 4" which is fine but as RD says make sure the pitch is checked to allow for proper draining. It is best to drain the condensate away from the direction of steam flow.