Single Pipe Steam Balance Issue - One main vs the other

bvaughn76

Hi, I am sure there will be more information asked than I can share at this second, but wanted to get the question out there. I have two mains piped back to the boiler. One for the West side of the house and the other for the east side. The West side is 15 to 20 min slower in getting steam than the East which causes it to miss the heating cycle and those rooms may not get heat.

I bought the house 5 years ago and have been making improvements after reading Mr Holohan's book and coming here. The west side has always been slower, but I don't remember it being this bad.

The East side feeds 5 radiators and 2 radiators in an addition that I recently updated and at that time I redid the main piping and drain as it was a total hack job. At that time I put Qty 4 No.1 vents on the SE end of the main and another No.1 Vent on a branch serving the radiator on the west half of the addition. The NE end of this main has no venting (yet). So, the East comes off the boiler and then hits a "T" and goes North and South.

I'm wondering if my issue is now that the East side heats way quicker than it has in the past and therefore there is a large difference between the two.

So, the West side main looks to be piped correctly. Piped up to the high spot, then pitches down to an elbow which has a condensate drain on it and the elbow goes up over the main beam and from there everything pitches down to end of the main where I have a condensate drain piped back to the boiler. Before this weekend, I am not confident the main pitched perfectly, there was a 2x4 holding up the end to try and get the condensate pitched right. There also were no vents. This weekend, I removed the the end of the main, removed the 2x4 and checked the pitch. I then added a tee to put in 4 main line vents. Put a 2" to 3/4" bushing, an elbow, then 3ft of 3/4" pipe to an area I had clearance to put the vents. All the piping pitches back to the main. I then repitched the whole condensate line back to the boiler. Fortunately there was a huge slope on the last segment to the boiler, so I had some room to lower the rest.

This fall, I hot skimmed the boiler and got out a lot of crap. I added in 8-way boiler water treatment, skimmed again, and added the treatment again for preservative.

So, the west is still 15-20 min slower. All that work and nothing to show for it other than ripped looking triceps from taking apart that 80yr old pipe. When the west finally does start to get steam, listening to one of the radiators upstairs on that end, the radiator breathes. I also tried a heating cycle where I significantly loosened the union just before the vents (to make sure the cheap main line vents I got at HD were not all stuck shut) and did not get any air out for a really long time. The east side is venting air out minutes after the boiler fires. The west side vents are doing nothing for another 15 to 20. What could be such a difference?

Hap_Hazzard

Are your returns wet or dry?

(Pictures would be a big help.)

JUGHNE

Does each main have a return coming back to the boiler ?

Can you post a picture of that piping at the boiler, floor to ceiling?

acwagner

What kind of main vents are you using? Gorton #1's?

Fred

Need pictures! Size of each main, length and diameter, number and size of radiators on each main, type of vents on each radiator, number and size of vents on each main will all affect steam balancing. Steam is going to take the path of least resistance.

JUGHNE

I was wondering if all the dry returns dropped below the water line before being connected together.
But looking at previous pictures by this OP they look OK at the boiler.

bvaughn76

Boiler 1 - Header


Boiler 2 - Return Piping at Boiler


West 1 - First section from boiler


West 2 - Second section from Boiler


West 3 - Heading North


West 4 End of Run


West 5 New Vents


West 6 - Detail of new vent and return piping


West 7 - Return


East 1 - Main looking north (no main vent at this end)


East 2 - Going south


East 3 - South End of piping


East 4 - South End Vents


East 5 - Run to radiator on west side of addition


East 6 - Vent on run to west radiator in addition


I likely have the sqft calcs of the radiators(corrected), but I have to dig that up somewhere. 13 total radiators. 8 on the East Main and 5 on the West.

I have the runs measure, but it is ugly and I need to draw out nicer.

Fred

Your first pictures say Boiler 1 and Boiler 2. Your last statements then says you probably have the Sq. Ft. Calcs for the Boilers. Are there two boilers involved in this installation and if so, are they tied together somehow or does one service the west side of the house and one service the east side.

bvaughn76

Mains are 2". Mains have been there how many dozens of years. The installer put a reducer right at the boiler. I know.

Returns are all 3/4".

Vents on the East Main are Maid o Mist #1.
Qty 4 on the Main, Qty 1 on the run to the SW side

Vents on the West Side are cheap Home Depot ones. I was in a pinch and figured they would vent for a while and then swap them to Gorton No. 1 after Thanksgiving and I am home for a bit.

Vents on radiators shown on diagram. Know all but 3.

CantabHeat

Could just be the angle of the picture but your West 3 picture looks like the line coming off the main dips down before rising again leaving a spot that could fill with water and block steam.

acwagner

There's A LOT going on in these photos, so it's hard to follow. But, my guess is this sharp down slope is causing the one branch to lag behind the other shown here circled in red:



I have a similar main setup that goes over a beam and then down. That main on mine is much slower for steam compared to the other main, even though the total pipe lengths are pretty close. My theory is the steam fills the pipe from the top down, so it hangs up there for a bit until the main fills completely up before continuing on.

On mine, I had to massively vent that main compared to the other main to compensate.

BobC

Breathing sounds in a radiator (also called panting ) indicate water is trapped someplace on the pipe leading to that radiator. @acwagner comment about that pipe having a possible dip in it is worth looking into.

Bob

ChrisJ

BobC said:

Breathing sounds in a radiator (also called panting ) indicate water is trapped someplace on the pipe leading to that radiator. @acwagner comment about that pipe having a possible dip in it is worth looking into.

Bob

Not necessarily.

My system does this as well when steam is heating the piping. Mainly because the steam goes a certain distance and then cools, dropping pressure and pulling more steam down the pipe. It "inch worms" down the mains, so to speak. No condensate involved. The system pressure goes between a slight positive and slight negative during it.

I've only noticed it on my system, perhaps due to how I have things vented.

@bvaughn76 what size is your boiler and how much radiation do you have?

EBEBRATT-Ed

Picture "west heading north" looks like a dip in that pipe

also vents are getting waterlogged too close to pipe and coming off the end of the main in pictures "east 6" and "south end vents" try raising vents or vent the riser at he end of the main

Hap_Hazzard

BobC said:

Breathing sounds in a radiator (also called panting ) indicate water is trapped someplace on the pipe leading to that radiator.

When steam encounters a puddle of water, it collapses with a bang, not a whimper. Panting is just due to steam entering cold pipes.

ethicalpaul

I'm not sure of that (although I'm not disagreeing either because it's hard to tell for sure the water level in my pipes). I have one upstairs radiator with a pretty definite flooded valley caused by house settling and it basically pants all the time.

It's hard for me to remember every detail, but I think it used to bang until I improved the situation at least partially, and now it pants, never bangs.

Is it possible that in a partially-flooded sag or valley, the steam would condense heavily but not bang?

After all, in both counter-flow and parallel systems, the steam is constantly in contact with a river of condensate at the bottom of basically every pipe.

Chris_L

It doesn't always bang.

Here is my experience with a slight dip in a radiator runout:
https://www.youtube.com/watch?v=rCyIqHmZLLc
And well before it got to the point of the gurgling water getting into the radiator, the radiator was panting away. Never any banging, never any water hammer.

And the radiator heated--but not as well as it should have. I fixed the pitch, it is now completely silent, and it heats much better.

ethicalpaul

OK that’s awesome. I know mine must be doing the same. It doesn’t get hot either. I have a plan to re-run the riser inside the living space instead of in the cold wall too

Hap_Hazzard

Videos on steam hammer:

https://www.youtube.com/watch?v=bDItSUeykrA


https://www.youtube.com/watch?v=JyvoN1hIqRo

Hap_Hazzard

Chris_L said:

It doesn't always bang.

What you're showing there is just the steam propagating waves as it tries to push the condensate back into the radiator. (The second video calls this differential shock.) That's a whole different thing. What I'm talking about is steam encountering pooled water in a pipe at the beginning of the heating cycle, where the water has had a chance to cool down. This causes a violent collapse of the steam cloud because the steam cloud contracts, causing the water to boil, which makes it expand, so you get a sudden drop in pressure followed by an even greater increase, commonly known as steam hammer.

Panting, on the other hand, is caused by steam condensing against cold steel pipes, which is much less violent because the steel has a lower specific heat and it doesn't boil.

The gurgling you're showing in your video is also less violent because the steam and water are in thermal equilibrium. It's just that the velocity of the steam is creating a lot of turbulence and wave propagation in that glass pipe. This is probably why the dead men usually kept those pipes shorter.

Chris_L

What I am showing is how a dip in the radiator runout caused water to collect at the low point and get forced up to the radiator resulting in the gurgling noise.

With the insulation removed, here is the pipe pitch causing the dip (main is about 2 feet to the right and radiator 12 feet to the left):
And here it is after the pitch was fixed:


The panting wasn't caused by cold pipes. In fact the panting of this radiator became most pronounced after it heated up--when the condensate pooled in the dip--without ever banging. (And none of my other radiators have ever panted regardless of how cold their pipes were.)

Hap_Hazzard

Yeah, what you're seeing is a totally different phenomenon that panting or banging. You're seeing differential shock caused by steam moving over water that's trying to go the opposite way. The second video illustrates this.

bvaughn76

Hi, I will find the radiator sizing this weekend when I get back from work.

Not sure where the Dip is in West 3. If you are referring to what you see in the distance, that is a takeoff for a radiator at the end of the main where my vents are.

Curious about the comment about the drop called out in west 2. What about in west 1 where the pipe goes over the main beam. Would that drain be potentially clogged allowing condensate to pool there? Piping from the high point at the boiler slopes to that drain. Main goes back up over the beam and then has pitch to the end of my main. I guess an easy check is next time I have a long heating cycle and get steam. On that side, if the drain is cold water would be sitting at that spot, right?

Also, only 1 boiler, sorry about the typo earlier.

I also like comment on my east vents. Noob mistake. Not acceptable for a forme I&C control engineer for nuclear plants. Guess being out of the biz for a decade made me dumber. Need to figure out a fix in that cramped space.

Fred

It looks like there is a drip on your West 1 picture, right before it goes up and over the beam. That should be fine, as long as there is another drip at the far end of that main (after where it goes up) and the main then pitches so the rest of the main can drain. Those drips are not likely to be clogged, at least until it becomes a wet return (where it drops below the boiler water line).
In your picture East 4, it looks like your vents are on the end of a main that pitches towards the vents, before the main turns. If that's the case, water can pool there or be blown into the vents preventing them from working. That vent tree should be turned up, with an elbow and go as high as possible.

Steamhead

@bvaughn76 , where are you located?

bvaughn76

@Steamhead I am in RI