Near boiler piping

TKPK

I have a near 100 year old home with a 30+ year old Weil McLain 2 pipe steam boiler that is working fine.

I am retired and learning more about this topic and have found a few issues with my boiler and wondered if this is a big enough issue to warrant fixing.

I have two risers that come to a cross with the outlet to the main above and the equalizer below.

I have an idea on the correct way to pipe this but wanted some confirmation on the issue. I removed insulation so you could see the cross.

if I were to re-pipe, I would think about a drop loop. I would connect the main with a T and continue on to the equalizer which would be connected with an elbo

1. How big of a problem is my current piping? Is it worth fixing?
2. Is the sketch the best way to correct? The drop loop probably is not necessary but if I’m going to fix it I might as well go whole hog.

Jamie Hall

In direct answer to 1 — if it's working fine, don't fix it. I can't say that I've ever seen that particular configuration, but… thinking about it it actually might work remarkably well. Leave it alone.

Your sketch acually isn't as good. If you were to do something like that, the equalizer should take off from one end of the dropped section. The sequence of piping across the dropped section should be riser, riser, main takeoff, equalizer.

KC_Jones

I agree with Jamie, if it's working fine, leave it. If the boiler was only a few years old I might feel differently. Since you say it's 30+ years old you are probably less than 10 years from a full replacement, perhaps 5 or less.

To mark up your drawing for how it's supposed to be piped see below. The header is supposed to slope down slightly to the equalizer. the main comes down between the equalizer and the last boiler riser.

LRCCBJ

https://forum.heatinghelp.com/discussion/comment/1821827#Comment_1821827

It would make his life much easier if you brought the right side riser over to the left and entered the header relatively close to the left side riser. This also provides much more time for the steam to drop water than would otherwise be available if the right side entered per the sketch. He could then keep the equalizer in relatively the same position as it is currently.

But, as stated, it's not worth all that work if it operates properly.

TKPK

I likely will take your advice and let the sleeping dog lie so this is more for discussion and understanding.

The reason I am drawing this as a loop is the risers are 2’ in front of where the main takeoff is. The main takeoff is also in the same plane as the equalizer.

My understanding of the basics of near boiler piping is:

1. Never have steam collide
2. Have the steam chase the water to the equalizer

The Original sketch and #2 use the drop loop to avoid prying the boiler apart with hot/cold cycles.

#2 and #3 have risers going to the header that stays on the same plane and follows riser, riser, main takeoff, equalizer. Are either of those better? This is the plan view of the current pipe positions

TKPK

#4 is how it would look if I revised the KC jones sketch and that doesn’t look right to me.

I really don’t want to touch the asbestos insulated main so I’m treating the riser and main takeoff positions as fixed.

TKPK

5 uses the drop loop and lets the equalizer still come off from the higher point … not sure if this is worse than 2 and 3

LRCCBJ

Since the risers and main takeoff are generally in the same plane, and the risers are quite tall, you don't need to resort to a drop header. What you have shown in #3 will work quite nicely HOWEVER, you MUST ensure that the header is pitched down to the LEFT, the piping going rearward toward the main is pitched DOWN, and the crossover pipe that is attached to the main is pitched DOWN toward the equalizer. If you screw this up, any water that accumulates in the header and the crossover pipe below the main will NOT make it to the equalizer………..which is where you want it!

109A_5

Hello TKPK,

With your original drawing (and #5) the drop header may fill up with water and obstruct the steam flow, not good. The drop header can not be a low point without a means to drain.

TKPK

thanks, that makes complete sense

Long Beach Ed

I'll tell you this… it's the first time I saw a cross used in a steam header. Not good, but, well, different.

Lance

What you have here is a well designed use of a cross tee. Both risers are tall, the ells provide a swing joint to handle movement. The only thing I would have done different is make the cross tee the size of the riser above it and bush down to the lower three connections. But since this connection may have been oversized it works. I donot like to bull head opposing flows together but it works. But like some have said, if it works. How can you argue against it? AS long as all three return drops are attached to the same Hartford loop its good. I see no worries with header condensate returning to boiler either way.

ethicalpaul

I wouldn’t call it well-designed but it doesn’t surprise me if it works

109A_5

I bet it works fairly well. Two tall risers, separates the water from the steam and slows the velocity down, at the cross the steam goes up to the lower pressure and any water gravity takes it down into the equalizer. Not typical by the book method, but I bet it works well enough to not mess with it.

TKPK

I think I was getting some carryover in my mains. I have two loops that circle the basement and the main vents are right above the boiler. The vents were on the drop elbo so I put them on antlers and upgraded the volume of vent. I tested the old vents and some were pretty restricted …had last replaced them ~20 years ago. I soaked them in vinegar and all but one revived. I put the old vents in the position that I thought were most likely to see a rush of steam and put Gordon #1 or #2 in safer positions and still have a few spares.

One of the loops splits and was slow so I put a vent right after the split where I had an available port. This is almost exactly at the 1/2 way point and before any radiator take offs. Now all 3 main ends get hot in ~3.5 minutes.

I have also been working on water quality, near boiler pipe insulation and reflective insulation on all of the radiator covers. I also change the setting on my thermostat from fast to slow. This has resulted in longer boiler run times instead of several 5+ minute runs. The system seems to be working better than ever. I really wanted to “fix” the NBP but that urge has gone away and I will likely be out of this house before a new pointer is needed. I’m still considering putting a sight glass on the equalizer so I can see how much water is getting carried up the risers.

there is a lot of good advice on this site that I wish I had seen 40 years ago

LRCCBJ

You've done a good job. Getting a steam boiler to perform properly is a series of incremental steps. Sometimes one step impacts the next. It's a slow process.

A sight glass on the equalizer will tell you nothing about how much is carried upwards into the mains. It will only tell you that a certain percentage (maybe even 95%) of the water is NOT going up into the mains. Worthless.

TKPK

It will tell you if a bunch of water is being carried up the risers! If system is behaving very well there will be very little to no water being carried up the risers and very small amount of condensation coming down the equalizer. The way my two risers collide at the cross and the equalizer drops directly at the cross I might have a bit more than if it was perfectly piped.

If there is a flood coming down the equalizer then you know a flood is going up the risers. Given that my equalizer never reaches near boiling temp I’m betting I don’t have a lot of water being carried up the risers

I think it interesting and a curiosity … not of great value but it would cost me much or be a big risk. As I said, considering but ultimately won’t do it …

ethicalpaul

it won’t necessarily tell you because the water could be going up to the mains and not down your equalizer (trust me, it happens)

Put the glasses here if you really want to see how dry your steam is. Installers should be doing that instead of using two pipe sizes bigger than directed by the manufacturer, then they’d see they are wasting customers’ money, but I digress

Even easier you can put a glass on the vertical drop at the end of your main to see if boiler water is exiting the main.

But really you can tell by watching the normal gauge glass for a sudden drop instead.

LRCCBJ

Paul, you might provide him with a better result if that glass is right at the top of the risers before the elbow. He'd be extremely fortunate if no water appeared at the two green circled locations above.

TKPK

@ethicalpaul

No doubt that would be he better location but this is a 34 yo boiler and I was advised (correctly I think) to not do major surgery on the NBP. Your setup is a dream and I envy you …

play around with minor surgery, maybe? (Prolly not)

So far I’m limiting to putting valves on the bottoms of the drops, sight glass and skim tap so I can more easily eject the mud. Also replaced the whole makeup water loop as it had a bunch of galvanized mixed in with copper. In that process I found and replaced one near rotted nipple and have failed to break a joint with some pretty large tools.

Also installed a 0-5 magnahelic and I am waiting for parts to swap the steel pigtail for brass…lots of insulation and venting improvements … etc

ChrisJ

https://forum.heatinghelp.com/discussion/comment/1823931#Comment_1823931

For what it's worth I stopped using a pigtail on the gauges / controls that I use during normal operation. I had too many issues with a pigtail and the slug of water causing calibration issues and delays with things. I use an 18" tall 1/2" length of pipe as an air gap to protect everything from steam. Nothing to clog or get dirty.

I still have a brass pigtail on the code required Pressuretrol and 30 PSI gauge of course and I inspect them and keep them operational. But they do not do anything during the normal operation of my boiler.

Here's a very old thread on the discussion.

https://forum.heatinghelp.com/discussion/152691/going-commando/p1

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1823902#Comment_1823902

I think it is rather typical that no water would appear at those locations, provided the correct size pipe was used. My boiler never shows a drop of water even directly above the boiler where my sight glasses are. And I'm currently running my water level at 1/2" from the top of the gauge glass.

ChrisJ

https://forum.heatinghelp.com/discussion/comment/1823936#Comment_1823936

You forgot the most important part.

And that the water isn't oily / dirty.

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1823931#Comment_1823931

Sounds like you have a good handle on tackling several issues there. If your water level in your gauge glass doesn't dramatically drop during steaming I think you can safely assert that your system isn't surging, and to my mind, that is by far the most important thing.

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1823938#Comment_1823938

Well that goes without saying!

LRCCBJ

https://forum.heatinghelp.com/discussion/comment/1823936#Comment_1823936

Somebody chastised me for making assumptions today. 😀

TKPK

https://forum.heatinghelp.com/discussion/comment/1823939#Comment_1823939

super good and insightful help on this site! Tyvm