Restoring One Pipe -- finally

cgutha · March 22

HI Everyone, I am finally restoring the boiler.

In a "Whole house" heating update, insulating the house came first. Who would have thought it would take this long? Most of the house is now insulated, new electrical and plumbing installed. It is winter, so I am doing basement things: water heater, now boiler.

The boiler is a Weil-McLain EGH-85. 350k input, 280k DOE output. At a design temperature of -30, The new heat load of the building is 240k BTUH. So, I am redistributing and removing the radiators according to calculated need. Given the fact that this year we saw -39 degrees, I am not worried about being oversized. I am reusing the 3" main but will only have 14 risers.

Originally, I had two mains, 3" took care of the East half of the house, and 2" the west half. They met on the other side of the house and came back in a wet return. I thought I had a picture of the loop where the two connected

but it is behind the wash machine. The return line is dry here but drops down to go under the floor at the stairway. Then went into a condensate tank, with pump.

Because my heat load has decreased, I can now send all the steam through the 3" main, reduce it at this junction, then continue around the house in a 2" main (change slope and direction of flow). This will allow the end of the main to be a few feet from the boiler. I will take pictures when I get that far.

The right section of the boiler leaked, and all the burners were rusted / unusable. The section is now replaced, and the new burners are in a box in the corner. I did a pressure test and decided to replace all the ropes and sealing rings. That is what I am doing today. I probably should have boiled (chemically clean) all the sections but did not. There is a lot of calcium buildup and rust.

The near boiler piping was welded, and not quite right. I am moving the boiler and have modified the header to make a dropped header — threaded. I will send pictures when I get it assembled. Now I have two more sections to clean and put together. then the left section is ready to connect to the right section.

Steamhead · March 23

This is in Velva?

Mad Dog_2 · March 23

Velveeta? Wisconsin? Ha ha..Mad Dog

Steamhead · March 23

Velva, ND. If that's the place I'm thinking of, I looked at that some years ago for a former owner.

cgutha · March 23

Yes, Velva ND. and you were here. You recognize the wash machine. it is still there. 3 phase, 3 hp belt drive, overhead shaft.

cgutha · March 23

The original coal boiler is still there, and some of the parts are still cluttering a corner somewhere. Part of me wants to remove it for the space, another part says keep it for a potential museum piece. most of the auxiliary equipment and piping has been removed. The old water tank leaked; I am waiting for help to truck it off.

The bricking is crumbling, but there is enough left that I can tell the original water level of the system.

Obviously, a wet return traveling under the basement floor returns condensate at a temperature around 65 degrees. I suspect that continuously adding 65-degree water to a cast iron boiler has something to do with the metal fatigue of the inlet section. I plan to eliminate that problem by employing dry return. With the change in the main, the main now ends a short distance from the boiler. thus I will try to maintain 212-degree saturated water at the Hartford loop.

Steamhead · March 24

Or, if the return has to stay buried, insulate it. We generally do.

And I bet a steam or gas engine originally drove those lineshafts.

cgutha · March 25

Now for the near boiler piping: 24 inches from the water line, can it be taller than this? how tall is too tall?

ethicalpaul · March 25

It can be taller. There is no "too tall" for a header but there is "unnecessarily tall".

If the water is reasonable quality, it won't even splash above the boiler anyway.

Hap_Hazzard · March 25

https://forum.heatinghelp.com/discussion/comment/1849810#Comment_1849810

It's not just a matter of how high the water splashes; it's how far the droplets get carried by the high velocity steam column. That's why they call it carryover.

ethicalpaul · March 25

The velocity isn't high enough to carry them over, if the size and number of the supplies is anywhere at all close to manufacturer's specification.

But lots of people sure think it is, even though they have never seen it.

And just for fun, let's say the velocity is high enough. The drops don't stay suspended. They eventually hit a pipe wall and stick to it.

Hap_Hazzard · March 25

https://forum.heatinghelp.com/discussion/comment/1849857#Comment_1849857

There's something called entrainment where the droplets stay in the steam train until they're physically separated from it, such as going around a bend and hitting a pipe wall. That's the idea behind the header. But how much separation occurs depends on the velocity at the point of separation and the size of the droplets.

Have you ever put a sight glass on your equalizer to see how much water is coming back to the boiler from the header? If you haven't, that's going to be my next project.

ethicalpaul · March 25

entrainment is another myth that people think exists yet no one has ever seen. I'm not saying it could never happen, but it never happens in residential steam. The drops fall out and hit a wall, with or without drop header. Residential steam isn't very fast. The bigger the boiler, the bigger the pipes so the speed is limited.

"That's the idea behind the header." Not to be arrogant, but who are you talking to here? 😅

There is no water coming back to the boiler from the header, unless the water quality is bad enough. See my videos.

At startup there will be a very small amount sliding down the pipe wall but once everything is hot, the condensate in the header becomes steam again before it even has a chance to drip back to the boiler. The steam passing by re-vaporizes it.

Hap_Hazzard · March 25

Of course you can't see it. Are you going to tell me wind is a myth because no one has ever seen it? It's a real, measurable physical phenomenon. https://www.sciencedirect.com/topics/engineering/liquid-entrainment

I've looked through your videos. I didn't see one that adresses this.

ethicalpaul · March 25

I'm saying if they are so small that they can't be seen, they don't affect anything.

The examples on that page are very small tubes. At our speeds and size of pipe, there is no measurable effect.

Note from your links: "In annular flow, liquid forms around the inside wall of the pipe and gas flows at a high velocity through the central core. It occurs for gas velocities greater than 20 ft/sec (6 m/sec)."

This video shows the utter lack of carryover and entrainment:

https://www.youtube.com/watch?v=4IymyZB4wlI

Hap_Hazzard · March 25

You wouldn't be able to see it there. The droplets are too small and moving too fast. I mean, I don't "see" any steam there either. Does that mean there's no steam there?

ethicalpaul · March 25

come now.

Hap_Hazzard · March 25

I'm sorry, but, "if I can't see it it isn't there" isn't a great argument.

ethicalpaul · March 26

"Too fast to see" isn't that great either. This isn't a jet engine, it's a pot of boiling water. Your links regarding entrained mist are talking about much faster flows in much smaller pipes (and the ones referenced there are not invisible).

Do people think these invisible droplets (if they are there) affect anything? Do people think that a few curvy pipes remove would them if the forces that entrained them are so strong? I know you put sight glasses on your boiler, but I can't remember if they are on the supplies.

When I asked people what wet steam was in that thread some time ago, I don't recall anyone saying "it is droplets that are too fast and too small to see that apparently don't affect the water line". I know that people don't like it when some picture they have in their mind for years turns out to be different in reality but folks have to trust their eyes at some point.

Here's what I think surging and carryover and wet steam actually are. It affects the waterline and steam "efficiency" (maybe) and is obviously not desirable:

https://youtu.be/jvt8qxBaRJU

Jamie Hall · March 26

Saturated steam —which is what we are dealing with — will always have liquid phase water droplets in it. They are constantly forming and evaporating. And no, usually you can't see them. They will coalesce on cooler surfaces, such as pipe walls.

If there are larger droplets — in the visible range (still pretty small) that's when bends and such are helpful, as if the velocity is anything reasonable they won't make the curve.

The best research on all this actually comes from aviation, as a lot of work has been done on icing on airfoils, enough of which can ruin your whole day…

ethicalpaul · March 26

Saturated steam —which is what we are dealing with — will always have liquid phase water droplets in it. They are constantly forming and evaporating. And no, usually you can't see them. They will coalesce on cooler surfaces, such as pipe walls.

I agree with this—this was one of my definitions that I put in the poll on that thread. But almost nobody around here felt that was what "our" definition of wet steam was (I had made the statement that by definition, all of our steam is wet steam). (See the fourth choice in the poll here)

So now I set that definition aside since I also agree that it isn't useful for residential steam since it's in fact ever-present and there's nothing we can do about it (we don't have super heaters on our boilers). But I think that's what @Hap_Hazzard is referring to (but I don't want to put words in his mouth)

cgutha · March 27

Wow. (And I am not even talking politics on Facebook.) If you wish to discuss super heat and steam engines, I recommend Steam Automobile Club of America | Steam Engines and More (can I do that?)

I have a nine-foot ceiling in my basement, so 36 inches from the top of the boiler case to the center of the 'hook' that drops into the header is no problem. Which is about 46 inches from the water line.

It looks like an eight-inch pipe between the takeoffs, and header will align my header with the condensate return port of the boiler. (Someone should have mentioned that in the boiler manual somewhere.)

Dan mentioned in his 'Lost Art' book that we are shooting for dry steam to increase efficiency of transferring latent heat, so I am striving for dry steam.

By the time the main wraps around the house, I only have about thirty inches to the water line. That is still above the required 28 inches. I have some changes to make, I will know more exactly later.

by the way, the speed of the steam in the two-inch boiler risers, at maximum output is 44.6 feet per sec. lots of carry over.

ethicalpaul · March 27

30 inches, 28, 12 it’s all fine. On one pipe systems for sure, the waterline doesn’t rise at the end of the main

Hap_Hazzard · March 27

Of course you can do that, @cgutha . It's your thread. Sorry I took it on a tangent, but some of us see the IOM rrecommendations as a maximum, while most of us see them as a minimum, and, when it comes to header height, if we're working with two 2" boiler risers and two 2" system risers, the amount of pipe it takes to get to the mains is the same, no matter where you put the header, so why not make it as high as reasonably posssible?

I got a lot of help from the people on this site when I was designing my header. Here's a thread where I specifically asked how high my header should be:

https://forum.heatinghelp.com/discussion/140885/how-high-the-header

ChrisJ · March 27

https://forum.heatinghelp.com/discussion/comment/1850103#Comment_1850103

The higher the header the more equalizer pipe you need.

That's all I've got………

Hap_Hazzard · March 27

https://forum.heatinghelp.com/discussion/comment/1850104#Comment_1850104

Yeah, you're right about that. Good catch.

Restoring One Pipe -- finally

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