Old Bryant steam boiler, and duty cycle

Precaud

Thanks @Chris_L , yes the power fail instructions are interesting.

PMJ said:

Right, the ratings are always for the total EDR(equivalent direct radiation) of the installed radiators not the house sqft to be heated. So I have 1000sqft(EDR) of installed radiation. The house itself is about 3500sqft.

OK, that makes more sense . I have not looked into the EDR of this setup yet.

I just took a look at the main vent. It is a Hoffman 16. I've never felt any air coming out of it so it may be clogged. And that brings up the question: is it worth replacing it, given the situation that @Steamhead exposed, where steam is going into the end of the main loop due to the pipe from the header tying in to the return well above the waterline?

Here is a map of the piping. The floor plan shows main floor; full basement is under (except porches and laundry room), where boiler is located. Boiler labeled"B". Radiators labeled "R". Active radiators are red, inactive (valves closed) ones in blue. Main vent is at the end of the main loop, above the boiler, marked V in orange.



As you can see, the last-used radiator is about 60% down that line.
In this situation, do I still want a functioning main vent, to pull steam down the end of the line where no radiators are being used? Even when that same vent will allow more steam to go directly from the header into the line end? Or should I leave the clogged main vent in place?

ethicalpaul

I would vent it. Does that first bedroom and the bathroom get warm enough?

But yeah I guess that would depend on fixing the waterline. Otherwise it doesn’t matter

Precaud

Thanks for your input, @ethicalpaul . The first bedroom is fine; the bathroom could use a touch more but is not bad. Perhaps I'll put a larger vent in that radiator.

Yesterday I removed all the vents and examined them. They're all Hoffmans, the main a #16, the radiators are all #40's. All of them are quite clean inside, no buildup of any kind. The #40's open/close just fine, which is impressive after at least 30 years of operation. The #16 is nonfunctional, doesn't pass air either direction, even after boiling in vinegar. I'm going to order a Gorton #1 and experiment with it. Now that I understand what's going on with the piping there (yeah, it took me a while), I'm pretty convinced it won't make any real difference. Steam willl get there more quickly, close the vent, and then it behaves the same as it does now.

The L604A-1169 Pressuretrol arrived yesterday. BNIB, just as advertized. A heckuva good deal on an item no longer made.

nicholas bonham-carter

I don’t think a Gorton #1 will be big enough.
A Gorton #2 is good for about 20 lineal feet of 2 inch pipe, and is more than twice the capacity of a #1.
Try timing firing the system from hot, with the main vent removed, until steam comes out the empty tapping.
Put enough main vents to arrive at that time.—NBC

ethicalpaul

Well a #1 is good enough currently because the nbp is strange and is letting steam go backwards from the boiler to the main vent

Precaud

mattmia2 said:

If you could find a place to add a main vent or 2 at the far end of your mains that would help your balancing task greatly, if there is some fitting or stub you could take out and add a tee or vent to the main far from the boiler.

Thanks for the suggestion, I moved your question into this thread, where it really belongs.

I took a look, and it turns out that there may indeed be a place to vent the main just before the last radiator being used (in the bathroom, see drawing above). I've attached a pic of a pipe on a stub off the main, which used to go to a radiator that no longer exists.

Is this a legit thing to do - to vent a main in the middle of the loop? Why won't this allow even more steam to go into the return end?

mattmia2

Others will know better, but I think it will be the same as far as steam in the return. The steam is already filling the return from the boiler end then hitting the vent and stopping. If there is a vent on the far end steam will flow out to the far end of the main and fill the main better. What I don't know is how much of an issue the steam flowing out through the return will be. My gut is that it will be ok because the consensate can still get to the actual return, but I am not an expert.

Obviously the real fix is to get the return up high enough to keep that tee full of water, but this might be a decent stopgap.

You would need to take that cap off and get an elbow and vent on it so you need enough clearance for the vent.

Precaud

mattmia2 said:

Others will know better, but I think it will be the same as far as steam in the return. The steam is already filling the return from the boiler end then hitting the vent and stopping. If there is a vent on the far end steam will flow out to the far end of the main and fill the main better. What I don't know is how much of an issue the steam flowing out through the return will be. My gut is that it will be ok because the consensate can still get to the actual return, but I am not an expert.

OK thanks, let's see if anyone else weighs in on it.

Obviously the real fix is to get the return up high enough to keep that tee full of water, but this might be a decent stopgap.

The return isn't the problem. As @Steamhead pointed out, One of the drips from the high header ties into the return well above the waterline, pushing steam into the end of the main. So the tee needs to be moved down, by some 3 ft. That would be a summer project.

You would need to take that cap off and get an elbow and vent on it so you need enough clearance for the vent.

Yep. I'd do it now but the next 6-7 days is looking stinky weather-wise, so the system will be running without break. But I'll definitely check it out ASAP. Would definitely like to hear what others think about venting the main mid-loop.

mattmia2

Obviously the real fix is to get the return up high enough to keep that tee full of water, but this might be a decent stopgap.

The return isn't the problem. As @Steamhead pointed out, One of the drips from the high header ties into the return well above the waterline, pushing steam into the end of the main. So the tee needs to be moved down, by some 3 ft. That would be a summer project.


The other option is to bring the return from below that tee up in to a high loop then back down to the boiler creating a false water line in that return that is above the tee. I guess which makes more sense depends on if that is the only place that needs the higher water line of the old boiler or if you would need to do that fix in multiple places.

Precaud

mattmia2 said:

The other option is to bring the return from below that tee up in to a high loop then back down to the boiler creating a false water line in that return that is above the tee.

Thanks, but that sounds more complicated than just moving the tee down.

Gsmith

Yes putting a vent there until you get the near boiler piping fixed will help. Doesn’t matter that it is in the middle of the loop, it’s near the farthest point from the boiler if the loop is being fed from both ends. The purpose of the main vent is to let the air out of the main as fast as possible and putting as far from the boiler will help. You can remove it and put it at the end of the loop after you get the drip tied in below the waterline.

Precaud

Thanks to the solar heaters, the system was off all day and started from nearly cold tonight. As it did, I observed where the heat (hence steam) was flowing.

And to my surprise and dismay, it reaches the spurs to the shut-off bedroom heaters before it gets to the bathroom's. Which means that quite a bit of steam is flowing up through the return in reverse direction, and the bathroom radiator, in the middle of the loop, is the last to get steam.

So, I'd like to return to an earlier line of inquiry , with a photo posted earlier, plus one from a bit different angle. (Pls correct any errors in my terminology).




Pipe "C" connects the "lower header" to the "upper header", and carries the steam into the main. Below the "lower header", is the equalizer connecting into the bottom of the boiler, and to one end of the Hartford loop.
Pipe "B" is the "dry return", the end of the main loop, with the main vent atop it, and connects into the other end of the Hartford loop.
And pipe "A" is... what? What purpose does it serve, besides (undesirably) routing steam up into the return? @Steamhead referred to it as a "drip".

Today and tonight I have examined numerous photos and diagrams of 1-pipe steam systems with Hartford loops, and I don't see a pipe like "A", connecting the header to the return, in any of them.

So what purpose is "A" serving?
What would happen if it was removed?

From what I see, if removed, the system would then perform as it "should", with steam flowing only in one direction. from header, through main, to return.

Am I missing something?

JUGHNE

Pipe A is a "drip" for the upper header (horizontal pipe).
Meaning that any condensate formed there will flow down the drip......unfortunately in your case the steam also flows with it.
If it was eliminated the condensate would be trapped there and run back down "C" and collide with the steam coming up.
This would produce wet steam thru the system creating problems.

The drip should be connected down near the floor well below the boiler water line so it has a water seal to keep the steam at bay.

It is highly doubtful you will find your piping diagram in any book. It is the result of a boiler change out with creative piping that resulted in a much lower water line and made "A" lose it's water seal.

Precaud

Thanks for your patient explanation, @JUGHNE . I think I got it now. The mind is always looking for an easy way out of dilemmas

It is a wonder that this system works as well as it does...

When I replace it, the drip pipe "A" could be much smaller in diameter, yes?

mattmia2

Why does the condensate flow down a instead of c?(assuming the return is actually below the water line and sealed)

Precaud

The return IS below the water line and sealed. I can't answer your question, though that upper header does appear to tilt slightly toward pipe A. That short spur off the header may be a counterflow arrangement, it doesn't have a dedicated return.

Jamie Hall

You do need pipe A -- it's the equalizer -- but you need to reconfigure it so that it joins pipe B well below the water line of the boiler. I see a handy dandy union on pipe A, which will make changing it easy enough, but... is there a union somewhere nearby on pipe B? Be nice if there were...

JUGHNE

So if the left steam main is counterflow delivery, (sloping to drain back towards the boiler) then the "A" pipe is the drip for that main and also the 2nd horizontal header.

All the condensation taking place in the left steam main/radiation has to flow back against the direction of the steam flow in that single pipe. Without "A" pipe then that water would flow back thru the top header and down to the lower drip pipe"C" colliding with all the steam put out by the boiler.
With the slope on the top header draining towards "A" pipe then that return water is diverted from the boiler steam piping.

I see the capped stub on your main. Ideally if that were in the center of your steam piping "loop", so to speak, (in theory anyway), a large air vent would maybe improve the rate of steam travel speed..........could also throw any balancing you have out of wack. If you do this, I would install a full port ball valve under the vent so you can experiment with the new factor.

Precaud

Jamie Hall said:

I see a handy dandy union on pipe A, which will make changing it easy enough, but... is there a union somewhere nearby on pipe B? Be nice if there were...

Yes, at the very botom of it., there is.

JUGHNE said:

So if the left steam main is counterflow delivery, (sloping to drain back towards the boiler) then the "A" pipe is the drip for that main and also the 2nd horizontal header.

Referring to the 1st pic above: there are two pipes off the upper header. The one that comes off at a 45º angle is the short counterflow run I referred to. It feeds two radiators and is working fine. The one that comes off vertical is the main parallel loop. The top of pipe "B" is the return for that loop; you can see the main vent just behind the elbow.

dopey27177

Each dry return needs to be tied into the wet return. additionally when you do this put in another vent valve.

At 7000 feet elevation to have steam temperatures of 215 degrees you need to operate at 12 PSIG.

Your pressure control looks like it is set at 15 PSIG.

Set your cut out at 12 and the cut in at * this will allow the vent valve to cycle.

Jake

Jamie Hall

At 15 psi gauge, you'll be very lucky indeed if your vents survive, never mind operate properly (just a random pick -- the maximum operating pressure for a Hoffman #75 is 3 psi gauge; the maximum survival pressure is 15 psi gauge).

mattmia2

also, it is kind of like a free vapor system being at altitude. It will transfer heat to the water more efficiently.

JUGHNE

Jake, are you thinking hot water or steam?

Hap_Hazzard

Does hot water have dry returns?

Precaud

mattmia2 said:

You would need to take that cap off and get an elbow and vent on it so you need enough clearance for the vent.

I spent most of the afternoon trying to remove that cap from the stub, with no success. It's been there for decades. After removing the paint, I tried everything; soaking in WD40 (it's not really soaking with a horizontal pipe) , smacking it with a hand sledge with a heavier one backing it, heating it up, all the known tricks. I couldn't get it to budge.

It was a good idea, but sometimes you just have to punt.

Hap_Hazzard

Penetrating oil doesn't work on pipe joints that are sealed with pipe joint compound. You just need a lot of elbow grease.

Precaud

I guess I'm not as strong as I used to be....
(Fleetwood Mac)

Hap_Hazzard

I probably never was as strong as you used to be.

I bet you're holding something back because you don't want to break something.

JUGHNE

You can saw on the cap, you would saw parallel to the nipple, perpendicular to the plane of the pipe threads.
Saw deep on the edge of the cap where you know there are no nipple threads, then carefully angle saw into the cap where you know the pipe threads are, almost to the pipe threads. Then drive a cold chisel/wedge into your cut near the end of the cap. You are trying to split the part of the cap that is on the nipple. It will lose it's grip on the nipple and then unscrew.

You could also use an angle grinder for the cut,
Just do not hit the threads of the nipple.
It may take more than one cut.

Safety glasses are needed for either method. Chisels can pop out.

Precaud

Thanks for that info, @JUGHNE , it's very helpful.
I think I'll wait until a bit later in the heating season to do it, when we usually have warm spells where heating isn't needed. That gives me some recovery time in case I screw something up

Precaud

This morning I measured pipes and radiators and came up with the relevant numbers.
MAINS:
The header is 3" pipe.
The main parallel loop is 48 ft of 2.5" (1.6 ft3) followed by 47 ft of 2" (1 ft3), total 95 ft long and 2.6 ft3 volume.
It is operating now with no main vent.

The short counterflow main is 14 ft of 2" (.30 ft3) and 4.5 ft of 1.5" (.05 ft3), so 0.35 ft3 volume.
It also has no main vent.

RADIATORS:
Eight total. Six on the main loop (two inactive) and two on the short spur (one inactive). Using a chart in a Peerless PDF on system installation/sizing:
Total EDR = 371 ft2
inactive - 133
active EDR 238 ft2

BOILER:
The spec sheet says "Installed Radiation ft2" = 342
So its size is in the ballpark for using all 8 radiators.
About 33% oversized for driving the 5 active radiators.

Takeaway: It really needs functional main venting. The numbers say the Gorton #1 I got is woefully undersized for the main loop. I'm thinking, since all of the active radiators are in the first 2.5" section, and the possible location for a vent is at the loop midpoint, something in the 1.1 to 1.6 cu ft range would be good, no?

And second, since there is only one active radiator on the short main, and there's no provision for a main vent on it, can I just size that radiator vent appropriately?

dopey27177

To JUGHNE

I am speaking steam. If his home is at 7000 feet above sea level and his radiators were not sized to provide the the proper heat by using higher edr radiation to compensate for steam temperatures at lower pressure he will need to operate his system at higher steam pressures.

Whoops read the chart wrong.

Operating pressure is good at 5 PSI steam temperature 217 degrees F.

Water boils at 199.1 at 7000 feet

Sorry for the screw up.

Jake

Tim McElwain

It looks like the gas valve (Honeywell) was replaced at some time. The valve has a built in regulator so the regulator ahead of the gas valve can be removed.

Precaud

I got the cap off this morning. I read in a diffferent thread that Mr @JUGHNE used dental picks to completely clean the threads outside the joint, then soak in the vile chemical substance of your choice, let it set for a while, and remove. It worked. Doing it in the morning when I have more strength probably helped too. The vile substance of choice was a 50/50 mix of Liquid Wrench and acetone, to soften the layers of oil-based paint accumulated there. I found no pipe dope inside.

Given the age of these pipes, the inside doesn't look too bad. A little wet. A little rust. I was expecting worse. This pipe is on a runout a couple feet upstream of the last active radiator. I know the recommendation is for a foot or two after. But this will have to do.

So now I can order the adapters etc to put a main vent there. Am considering two MoM #1's on a tee, or a Big Mouth. The latter is attractive (well made, repairable) but seems to have high incidence of leakage and spitting water.

Thank gawd for Supplyhouse.com . Despite this being the state capital, we have no good plumbing supply outlets. We have the two big-box stores, but they stock only the stuff that is used the most, mostly galvanized in 1/2" to 1". Almost nothing in 1/4" brass or iron. Very little iron, period.

Precaud

mattmia2 said:

You would need to take that cap off and get an elbow and vent on it so you need enough clearance for the vent.

Exactly. Now that the cap is off, the question is, what to put there, and how. Here's the pic again.



The 1.25" stub is angled a little into the pipe for good drainage. But there is not much room above it for vent(s); 4" to the ceiling. This is a basement bathroom with shower, so I don't want to make a hole in the ceiling.

There is not enough room for a Big Mouth on an elbow ( >5.5" tall). Not enough room for 2 or 3 Gorton/MoM #1's on a tee or cross with elbows. They're 3.5" tall plus the elbow height.

One thing that would work is three Gorton/MoM "D"s on a cross with bushings. The D has the same vent capacity as the #1, but are 2.5" tall, 90º angled, and mount at the middle of the pipe, not on the top.

So 1.25" to 3/4" reducer -> short nipple -> 3/4" cross -> 3/4" to 1/8" bushing (x3), and screw the #D's into the bushings. That would fit. And be easy to service.

Wha'dya think of that?

neilc

does that point at a partition wall, that you could extend thru, and not care about the ceiling on the other side ?

Precaud

No, the bedroom on the nearest wall is also finished.

JUGHNE

You could put a reducing 3/4 reducing 90 with a street 45 to go to a horizontal nipple with Tee or 90 up for your vent.
Make horizontal nipple 8 to 12” long. This length gets your vent away from water slugs.
Just so every thing slopes back the to the main to drain .

Precaud

JUGHNE said:

You could put a reducing 3/4 reducing 90 with a street 45 to go to a horizontal nipple with Tee or 90 up for your vent.
Make horizontal nipple 8 to 12” long. This length gets your vent away from water slugs.
Just so every thing slopes back the to the main to drain .

I don't get it. What's the point/advantage of this? With what vent? What is a "water slug"?

JUGHNE

A water slug or debris can head for the vent and plug or damage it. As I think more about your vent a 6” nipple would suffice.

Would this give more head room for vents?
Straight connected vents would more desirable as they can drain any water down.