Pipe size

rtv · December 2014

This has always bothered me...when the boiler was installed the guys took 2" pipe from both outlets and combined them into a 2" T then into the existing 3" system pipe. shouldn't they be combining the two 2" pipes into a T with a 3" leg? Or am i making too big a deal out of this?

nicholas bonham-carter · December 2014

yes it is improperly done, and will cause you some grief.
download the piping instructions, and you can show them where they went wrong.--NBC

Fred · December 2014

Those pipes look larger than 2" pipe but it's hard to tell from a picture. Anyway, the risers up from the boiler look fine, the Header (horizontal pipe) should be at least one size larger than the risers and the riser to the Main (system Pipe) should always be after the boiler risers, down towards the Equalizer (pipe that runs down to the back of the boiler) with usually about 15 inches between it and the equalizer. Never inbetween the risers.

rtv · December 2014

So...you're saying it's even more botched than I thought!?

rtv · December 2014

And now that i've see the Weil-mclain instructions it seems they tried to do the EGH piping on an EG boiler. although having 2 risers instead of one probably wouldn't be a problem. Any thoughts on whether it's worth fixing or just live with it?

SWEI · December 2014

With 3" pipe on the system side of the companion flange, you almost certainly need at least a 3" header. Are there any tees nearby on the system side, or does the main run out for a bit before splitting?

What size is the boiler?

nicholas bonham-carter · December 2014

those unions on the header, and takeoff would make it a fairly easy job to move the risers over to the opposite side of a [larger] header from the equalizer.
has it been long since it was installed, and was it sized properly from the EDR of the rads?--NBC

Fred · December 2014

The fact tht they installed two risers out of the boiler is a good thing. Don't change that. The other items I mentioned need to be fixed, 3 or 4 inch header (with a 3 inch main, I'd prefer a 4 inch header) moving the riser to the Main over to after the riser out of the boiler and the riser up to that main (system pipe) should also be three inches, from the Header to that Main (to take full advantage of the 3 inch Main).

rtv · December 2014

weil mclain EG40 125k btu input
yes..there is a capped T (the capped part is 2") just after the 3" turns horizontal

rtv · December 2014

NBC: it's been years and i'm certain they took no account what so ever of the size or number of the radiators! They never asked!

Fred · December 2014

You probably need to survey your radiators and do the EDR calcultions to determine how well the boiler is matched to your radiator EDR. You can buy a copy of Dan's Radiator EDR book at the store on this site. It will give you the Sq Ft. of EDR for each type/size radiator. If the boiler is too large or too small, there are some things that can help the situation but until we know what the total radiator EDR is, we can't offer much advise other than to recommend correcting that near boiler piping.
Are you experiencing any notable issues or did you just post for opinions on your near boiler piping to confirm your thoughts?

rtv · December 2014

I agree, it would be the right thing to do . I have been experiencing no major issues except a minor bit of hammer which is new. I was mostly writing to confirm my thoughts and to see if it was a big problem.

Fred · December 2014

Water hammer is an indication that water is setting some where in a pipe or radiator. Do you hear it is a specific radiator or pipe? If so, check that radiator and make sure the radiator itself is tilted back towards the steam inlet pipe (if this is a 1 pipe system ) or towards the outlet pipe (on a 2 pipe system). Also check to make sure the horizontal run to that radiator is pitched back towards the Main in the basement. Sometimes things settle a bit and pipes can lose their pitch.
If the hammer is actually in the large Main, in the basement, check to make sure it too is pitched in the right direction and that there are no sags in the pipe.

rtv · December 2014

the hammer is not a big deal...some of it could be just expansion. I just checked out 3" black pipe fitting & nipple pricing! !! I think I can re-arrange everything except the 3" system pipe, to move it i'd have to make a few right angle bends (which i think might be a bad thing to do)

rtv · December 2014

I'm sure that you will think me crazy but I really do miss my old monster boiler from the early 1900's. unfortunately nothing lasts forever!

Fred · December 2014

Not a bad thing to do. As I see it, it's just 2 elbows. A street elbow where the new pipe joins the old Main piping With the stree elbow, take the lower half of the flange off and mount it on the threaded end of the elbow and remount it to the old pipe. There is a gasket in that flange that you can get at any plumbing supply house. Carry the pipe over to the header, where it turns to go down to the equalizer. When you put the new header in, use two nipples and a Tee insead of that long pipe, put another regular elbow on the pipe that you carried over to there and drop it down into the new Header Tee. Use a couplin in the pipe that drops down so you can connect the pipe together.

If you are going to rebuild the header to make it right, it only makes sense to make the whole thing right and it's a minimal amount of additional work.

rtv · December 2014

so there is no problem with right angle bends in the rise to feed the main system pipe?

rtv · December 2014

what is the reason for not putting the connection to the system between the risers. what happens?

Fred · December 2014

Steam from each riser collides with each other getting to the main. more turbulance

rtv · December 2014

got it...and no problem with the bends going up to the system pipe?

Fred · December 2014

not at all

rtv · December 2014

thanks for all your help! it should be an interesting project.
i think i might wait till temps rise before beginning though.

Fred · December 2014

Yea, changing out a Header, while it doesn't look like it should be to difficult to take yours apart, If you are getting decent heat right now, i'd wait till you have a few mild days so you can take your time.

rtv · December 2014

YUP!!! Thanks again!

SWEI · December 2014

rtv said:
weil mclain EG40 125k btu input

3" pipe is already one size larger than the minimum specified in the EG manual. Any idea if radiators have been removed since the house was originally built or heated? I'm wondering if the oversized piping might have been part of an old vapor system.

yes..there is a capped T (the capped part is 2") just after the 3" turns horizontal {image above}

That looks like a low spot in which condensate would settle.

KC_Jones · December 2014

I didn't see anybody mention these couple items so I thought I would chime in. Another thing missing on that header is swing joints. The risers from the boiler should angle forward or backward then connect together (as shown in the manual). Also the water feed is hooked in above the water line, this seems quite odd to me. Not sure if anyone else has thoughts about that?

Fred · December 2014

SWEI said:

rtv said:
weil mclain EG40 125k btu input
3" pipe is already one size larger than the minimum specified in the EG manual. Any idea if radiators have been removed since the house was originally built or heated? I'm wondering if the oversized piping might have been part of an old vapor system.

yes..there is a capped T (the capped part is 2") just after the 3" turns horizontal {image above}

That looks like a low spot in which condensate would settle.

That 3" pipe is his main. His Header is only 2", as are his risers. The risers are Ok but the header needs to be a minimum of 3".

rtv · December 2014

swei: this system is just shy of 100 yrs old...not sure if Weil Mclain specs were around then!

the original boiler was an old monster that probably was a coal burner then converted to gas. I think there now might be 2 less radiators than when it was designed.

Fred · December 2014

KC_Jones said:
I didn't see anybody mention these couple items so I thought I would chime in. Another thing missing on that header is swing joints. The risers from the boiler should angle forward or backward then connect together (as shown in the manual). Also the water feed is hooked in above the water line, this seems quite odd to me. Not sure if anyone else has thoughts about that?

The water feeder does not have to be below the water line as long as water drops down into the wet return to temper the cold water before it goes into the boiler. However, his appears to tie into the equalizer which means steam can get to the feeder. I'm not sure that is what you want. I agree, when he rebuilds the Header, he should use an Elbow off of each Boiler riser and then connect his Header.

rtv · December 2014

Ok I'll be sure to do that as well..with all these errors that are obvious (even to me) it makes you wonder about how people get to be boiler installers. I hope the guys that deal with high pressure systems are more "up to the task"!.

SWEI · December 2014

I understand it's an old system. The larger than typical pipes could be indicative of something interesting. It might be as simple as a few radiators removed at some point in it's history, but it also might indicate that the system was originally designed for especially low friction.

rtv · December 2014

SWEI: Interesting! please tell me more! from what i can tell it started with 9 rads and now has 7. The main distribution pipe does a complete circle around the basement with risers going up to each rad around the perimeter.

SWEI · December 2014

More square feet of radiation = more boiler horsepower and bigger pipes. Unless they're huge, 9 radiators is not all that many, but if the charts (at the time) told them to use 3 inch, they would have done so. Vapor/vacuum systems running at extremely low pressures would have used oversized pipes. Bigger really is better in this case, since it will lower the friction losses for you.

rtv · December 2014

well it certainly runs at low pressure! i don't think i have ever seen a reading on the gauge.

BobC · December 2014

Or your gauge does not work at low pressure; 0-30 PSI gauges are useless at the 1PSI level. If you don't have one, consider installing a 0-3 PSI aux gauge.

Bob

Fred · December 2014

Does the size of that main drop somewhere along the run or is it 3 inches all the way around the basement? I also have a 1 pipe system and I have one main that runs about 15 feet at 4 inches (believe it or not) (original 113 years old). At that point, the main branches off with a 2" short run and a 2-1/2 inch 50 ft. run. Both drop into the wet return in the boiler room. Where the 4' pipe reduces to the two runs, there is a Bell shaped reducer on the end of the pipe with the 2-1/2 inch run coming out of the end of it and the 2 inch run off the side. At the bottom of that bell, there is a 1 inch drip leg that runs back to the wet return in the boiler room. 15 radiators total but originally 17.

rtv · December 2014

it starts the perimeter at 3" for about 15' then seems to reduce to maybe 2" for the rest of the way around..it a bit hard to tell with the insulation covering.

Fred · December 2014

Very similar to mine. It's almost like the "Dead Men" wanted to make sure they reduced the velocity of the steam even more than the large header would do and also allow more water to drop out of the steam before it hit the 2" or 2-1/2" main. Almost like an extension of the Header.

rtv · December 2014

hi again..another question in this botched installation:
just had a look at the pressure gauge, it is installed before the pigtail! shouldn't it be after? like the cutoff?

Fred · December 2014

All of the boiler gauges should be installed on a pigtail but it is pretty typical for most installations to have the 0 - 30PSI gauge installed directly into the boiler block. They are pretty much worthless for day to day operation anyway. For the sake of argument, many (if not most) of those gauges are suppose to have an "internal syphon" or so they say.

rtv · December 2014

just ordered a 0-3 which i will try to "t" in somewhere (after the pigtail!) Thanks!

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