Replacing Near Boiler Piping with Drop Header

Brycewvu

I am going to be replacing the near boiler piping of my Weil McLain SGO-7. The existing piping is a single 2" riser, 2.5" header into 2 steam mains (one is 1.5" and the other is 2").

I plan to install 2.5" double risers into a drop header at 3" per WM installation instructions.

I have attached pictures of the existing setup but have a few questions before I post my final designs for your input.

1. I am going to take the back riser 12" forward then both across 15" to get around the flue pipe before dropping into the header. Most of the drop header examples I've seen look like they are only about 4-6" across the top. Is there any issues with having that extended dimensions on the drop header?
2. How far should the drop header go down? Is 8" ok or should I go 12"? I plan to take the riser 24" above the top of the boiler before turning and dropping.
3. The installation instructions say that the equilizer should be 1.5" minimum. Is there a benefit to do a 2" equilizer or just stick with 1.5"? I plan to tie in the equalizer where the coupler is on the existing piping. The existing return is piped in 1.5" and the boiler has a 2" to 1.5" bushing.
4. My water feed is currently connected into the front right drain port. I was thinking of relocating the feed into the back with the wet return. Any advice on where to put that based on what is in the pictures? Also, if I wait until next year to do the new water supply piping, is there a problem with piping a T in the wet return and plugging it until I get around to repiping the water?

Lastly (unrelated to the design), if I do this big repiping work, will I see a difference in my oil consumption and efficiency of the system or not really? If I am going to see a noticable difference in efficiency, I will push to get it done before the major heating season really gets going. If not, I will wait until the spring.

Thank for your advice!

ethicalpaul

1. What model boiler is that?

2. Is it surging?

3. Is steam getting to your radiators?

If the answer to 2 is "no" and the answer to 3 is "yes" then you will not see any difference in fuel usage, efficiency, or heating.

The answer to your question #3 is no, there is no reason to make the equalizer larger than specified.

Brycewvu

Its a Weil McLain SGO-7.

I usually only see the water line bouce about 1/2" while it's running.

Steam gets to the radiators just fine.

trivetman

why are you planning on repiping?

Brycewvu

Based on a few notes from a steam pro I had come take a look at things and the WM installation manual, the SGO-7 should have double 2.5" risers into to a 3" header. It currently only has 1 riser that is reduced to 2" and the header is 2.5".

My primary goal is to make my steam system as efficient as possible.

ethicalpaul

Yeah I probably have the same question. It is piped too small for the manufacturer specs, but on the bright side, the header is nice and high, it is topologically correct, and it sounds like it is operating well.

I would save the repipe for when/if you have to replace the boiler. Well to be honest, I can't say that because I replaced a whole boiler that was working pretty well even though it wasn't piped correctly.

Let me say it this way, and I'm kind of repeating what I said earlier…you won't see any difference in performance or efficiency. All the BTUs of fuel you are burning are getting turned into steam (well, at least the usual 83% or so percent of them), and all that steam is getting into your conditioned space.

But I'll answer your other questions:

1. It doesn't matter. You won't even need drop headers
2. It doesn't matter.
3. There's no reason to go bigger
4. You can put the supply water in the wet return. Anywhere that's convenient. You can put in a tee and cap it off temporarily.

Steamhead

@Brycewvu , that was me. Good to hear you're going to do this.

I think you will definitely get better efficiency from proper piping. One of the functions of the header and associated near-boiler piping is to separate steam from any water that is trying to leave the boiler with the steam. The current piping cannot do that. So the water comes up and quenches the steam, and the boiler has to make more steam than needed.

However, I would recommend holding off until at least March. It's getting cold, and that job is likely to take at least a couple days. You don't want to be without heat for that long.

Brycewvu

Thanks for the advice!

I purchased this house 2 years ago and have been slowly making improvements to the system as I learn more about steam. I installed a programable thermostat, replaced all of the radiator vents (7/11 were stuck open or closed), installed main vents, and replaced a leaky chimney cleanout to get a proper draft. If a big repiping won't change much, i will probably take that money and put in pipe insulation.

Brycewvu

@Steamhead I was wondering what your account was on here! Your advice and walk-through with me has been a huge help. Thank you very much!

109A_5

If you are not trying to cure a specific problem and if you don't need the basement as warm, I would spend the time and money insulating the mains and the runouts. If you are still motivated in the Spring do the near boiler piping then.

EBEBRATT-Ed

How old is your SGO-7?

If it was mine and it is heating well (sounds like it is) I would leave it as is. It won't save you any money on fuel and you can probably spend the money better on pipe insulation and tightening up the house. If and when you have to replace the boiler that would be the time to re-pipe. We see many boilers that are "piped wrong" and "shouldn't work" but they do. If it is steaming well and the water level is not bouncing or surging, and there is no water hammer I would leave it as is.

How does the size of the boiler compare to your connected EDR of the radiation?

New England SteamWorks

Insulate the pipes and upgrade the vents for the biggest efficiency gain.

Steamhead

https://forum.heatinghelp.com/discussion/comment/1818547#Comment_1818547

Vents are already upgraded.

New England SteamWorks

He has Gorton No.1s. I would put No. 2s

Steamhead

https://forum.heatinghelp.com/discussion/comment/1818580#Comment_1818580

I put those vents in. They are sized to the amount of air in the mains and dry returns, which are rather short.

New England SteamWorks

Then I absolutely stand corrected!

109A_5

Is there a hole in the floor for easy viewing ? Seems a bit odd.

ToddfromAkron

there is an old saying, the enemy of good is better. Yes, drop headers are excellent. Yes, 2 headers decrease the steam velocity coming out of a boiler, which results in drier steam.
However, it seems like your system is purring along just fine at this point.
The glaring problem I noticed from the photos is the complete absence of near-boiler insulation (or any insulation for that matter). The amount of heat lost during the first several feet of pipe is astronomical.
You can purchase the proper 1” rigid insulation and corner fittings at your local plumbing supply.
This will also make the steam travel faster and could pick up more water. There is a potential that if your steam is currently a little wet, adding insulation might actually cause the problems that you “should” be having with the current piping configuration and aren’t.
I’d still insulate the pipes. You could always decide to not completely secure the near boiler insulation at first to see if there are any problems that would necessitate a piping change.

LRCCBJ

One point that is typically ignored and would explain why your system works well, despite the undersized piping:

The goal of a header is to allow the water to fall out of suspension BEFORE the steam reaches the mains. On a typical boiler setup………..even by experienced professionals……………you will notice the second riser (when twins are used) is quite close to the first main. You have to ask yourself, how can the water drop from the steam when it has only a fraction of a second before it reaches the main?

Answer…………it can't.

On your setup, you have SIX FEET of header before the first main takeoff. This allows several seconds for the water to drop from the steam and continue on down to the equalizer. It sounds like nothing but it is quite significant.

It explains why you can utilize smaller piping and achieve the same result……………ADDITIONAL TIME of the steam in the header.

Steamhead

Unfortunately, @LRCCBJ , the other factor in this is velocity. If the velocity in the risers or header is too high, the water won't drop out of the rushing steam, and will be carried up into the system.

@Brycewvu , this is why I recommend repiping the header.

Mad Dog_2

You go for it. The system WILL perform better. I'm glad to see a person actively engaging their system. One of Dano's famous quotes come to mind: "Dont talk people out of how to spend THEIR money..." Mad Dog