Burnham 406 2 or 1 pipe to feed the main?

mr_ius

Hi there,
I have a single pipe system, natural gas converted from coal, probably in the 60s or 70s. I had a steam guy look at my system the other day and as he was thumbing through the manual and he said the system should have two steam pipes feeding the system, not one (as it's currently configured). He said the one pipe configuration is for if the boiler is being used for hot water instead of steam. The system works as is but has a number of bugs. Any opinions on feeding the second pipe into the header? The picture attached shows a plug that was under a knockout in the boiler casing. Wondering if it's worth doing the job. Thanks !

Ironman

Can you post some pics that show the boiler and header?

What issues are you having and what model/size is the boiler?

mr_ius

Hi Bob,
Here are a few photos.

mr_ius

The boiler is a Burnham 406. Issues we are having includes uneven heating of radiators. Radiators not heating. Never getting up to dry steam. The most we get is maybe 1/4 lb, if that. The boiler seems to add water during the running process and then is over filled next time it turns on.

mr_ius

Jamie Hall

Honestly, I'm not too surprised that you are having problems. That poor boiler isn't piped well. You should have used both outlets, not just one and the header doesn't look to be high enough above the water line (although it may be, just), for starters. Both of those problems will cause water to be entrained in the steam, and the boiler will lose water as it runs.

When you say your are "never getting up to dry steam", what do you mean? There is not pressure measurement for dry steam -- that has to do with the piping. You also say you only get up to 1/4 pound, if that. That should be ample. How is that being measured? You don't want to build pressure.

The uneven heating is more likely to be caused by a lack of, or improperly arranged, venting -- or both.

mr_ius

Hi Jamie, Most of the piping was put in about 100 years ago along with the original coal boiler which has since been changed to natural gas. Fortunately it would not be difficult to add in the second outlet. In the picture above the 3" plug in the header is visible. Maybe the old coal boiler had two outlets...

Regarding pressure, my understanding was that a steam heating system is most efficient when at 2lbs. I believe I read that in Dan Holohan's book the lost art of steam heating. I'm getting the 4oz reading from the pressure gauge on the boiler, but from what you're saying maybe that's correct.

The system never had any of the large steam vents put in throughout the system so now we're trying to figure out how many to put them in and what the ideal locations will be.

Appreciate your input !

Fred

The reason the boiler over fills is because the McDonnel Miller #67 Low water cut off is mounted wrong. It should be mounted straight into the tapping on the sight glass. That LWCO has a float in it that will add water wherever the float drops below the very top line in that horizontal pattern cast into the side of the unit. The way it is elevated, with those elbows, causes it to add water all the way up to near the top of the gauge glass. Not right.
Also, I see the blow down on that unit has a cap on it. Do you blow the water down through that unit once every week or two during the heating season? Do you test the unit to make sure it works? When is the last time it was taken apart and cleaned?

mr_ius

Fred,
Thanks for your feed back. I'm impressed you could see the elbows from the photos I posted. The manual I have says to install the LWCO the way you described but my heating guy (who is good but not a steam expert) said to raise it up with the dog leg as an additional safety factor. Originally I had it in the correct position. I'll lower back to where it should be. I was suspecting the level of the LWCO was contributing to the extra water in the system, but wasn't sure. Thought it might have been the water feeder.

The LWCO was taken apart and cleaned before I put it on there a few months ago. I put the cap on b/c it leaks. I'm draining it weekly. The LWCO works and I actually tested it again today. I have a brand new one I'm going to put on, but wanted to be sure about the height before I started cutting pipe.

Ironman

The header does look like it's too low. It should be at least 24" above the water line of the boiler. The boiler riser should not enter the header from the bottom, but from the side or, better yet, from the top to form a drop header. Like this:



This will produce 99% dry steam if you also get the water level corrected.

You definitely should be using both tappings, run full size to the header.

mr_ius

Hatterasguy,

Thank you for your input. You mentioned that the LWCO is too high and should be lowered, but also that the tapping height was irrelevant. This indicates to me that I shouldn't necessarily go directly into the tapping into the sight glass but rather that I should mount it so that my horizontal casting line is even with my low water mark. Any idea where I can find my low water mark? I've looked all over my boiler and didn't see one.

The only water line I found in the manual was at 26" from the ground but I believe that is where the water should be when it is turned off (Normal Water Level).

Best I can gather from images in the manual the LWCO should be horizontal to the lower tapping of the water column but want to be certain before I change the position. I'd like to get it spot on.

Fred

I have a Burnham also. If you use a nipple and tie the LWCO right into the Tee (behind the sight glass) that it is currently connected to, it puts you low water level at about an inch above the bottom of the sight glass. That is the quick connect configuration that both Burnham and McDonnell Miller ship and advise in their instruction manuals. That is where mine is and it works perfectly. Just take the elbows off of what's there now and you have the recommended configuration.

mr_ius

Bob, Thanks for posting the images. The latter one looks impressive. I believe (but am not sure) that both of the outlet tappings are on the top of the boiler so I don't know if I could run out of the sides with out tapping the boiler; which I think is beyond my means at this point. Looks like I am at less than 24" from normal water line to header though. Thoughts on what this implies for the system?

mr_ius

Hatterasguy, Got it, much appreciated !

mr_ius

Thank you Fred !

mr_ius

There's the second outlet tapping... Looks like it's gotta come out !

Ironman

mr_ius said:

Bob, Thanks for posting the images. The latter one looks impressive. I believe (but am not sure) that both of the outlet tappings are on the top of the boiler so I don't know if I could run out of the sides with out tapping the boiler; which I think is beyond my means at this point. Looks like I am at less than 24" from normal water line to header though. Thoughts on what this implies for the system?

The images were just to show how the header is done. You don't have, or want, to attempt coming out of the side. Both images are of a Dunkirk boiler which uses side tappings which none of us around here care for.

Here are a couple more images for clarity:

Fizz

Concerning your operating pressure of 4oz, that's terrific. Lower the better. Think you misread 2lbs of pressure in Dan's book. The Empire State Bdg is operated on less than 2lbs. In any event don't let contractor talk you into more pressure.

Fizz

Also, wouldn't be so quick to get rid of LWCO or pressure gauge. Also, if you have old vapor stat on boiler, keep it!

Fred

The Header should be a minimum of 24" above the water line and if you can use both top tappings that would be great, however, if the boiler is running well, it might not make sense to put that kind of money into re-doing the header until the boiler needs to be replaced. When headers are that low, they can pick up a lot of water, making wet steam. The higher the header, the better or a drop header is even better but the risers out of the boiler still need to be at least 24" above the water line.

mr_ius

Bob, do you think it would be worth re-piping the steam outlets into the header like I show in the photo? Perhaps letting one outlet feed into the header from below (as it is) and feed the second (currently plugged) out let into the header from above, or would you recommend feeding both from above as in the photo? Thank you for your feedback!

mr_ius

Got the new LWCO installed. Seems to be working so far. Any ideas how long it should take all the water to trickle back down into the boiler once it's been turned off?

Fred

mr_ius said:

Got the new LWCO installed. Seems to be working so far. Any ideas how long it should take all the water to trickle back down into the boiler once it's been turned off?

Typically not more than10 minutes, 15 at most.

mr_ius

Fred, my manual seems to say we only need 18 inches between the header and the normal water line. Thoughts?

mr_ius

mr_ius

Hi Fred, hours after I've turned off the boiler the water column hasn't returned to the normal water line. Any ideas on why the waters not coming back sooner? could there be some kind of air or water lock?

Fred

mr_ius said:

Fred, my manual seems to say we only need 18 inches between the header and the normal water line. Thoughts?

That's interesting. That does not look like an original drawing from the actual I/O manual though. It may be. I have the 411B which is a bigger boiler, same vintage. My book definitely says minimum 24" above the water line.
In any case, that is the minimum and if I were replumbing the risers/header, I'd go as high as I could. My boiler risers are about 45" above the water line. Just makes for dryer steam. If you were to do a drop header, the risers should be 24" minimum. If the boiler is heating well, I'm just not sure it makes sense to try to repipe it. May as well wait until the boiler needs to be replaced. Also, getting thatt plug out of that second tapping is going to be a nightmare.

Fred

@mr_ius , I just pulled my old I&O manual as well, vintage 1983, page 13. I do have the very same drawing and chart in my manual and it too says minimum of 18" above the water line. So, according to those instructions, your header height is in specs but I'd still want it higher.

mr_ius

Fred, Thank you for your feed back. If I do re-pipe it I'll go up to 24 or more and then come back down to the header to get the dryer dryer steam. We've had a a number of nightmarish old pipes we've dealt with but I guess we run the risk of cracking the boiler in the case of getting that old plug out... sufficient amounts of WD-40 and the acetylene torch might do the job... still if it cracks it's all for nothing...

Fred

At least the tapping/plug is facing down so PB Blaster or something similar can at least soak around the threads. At the end of the day it may have to be cut out. Just take your time. Personally, I'd wait until after the heating season to tackle that project.

nicholas bonham-carter

Sometimes, if the main vents are inoperative, the vacuum left by the condensing steam will slow down the condensate return, so how are your main vents?--NBC

Ironman

I have to agree about not attempting to re-pipe it unless it's absolutely necessary. If you have a failure while trying to remove that plug from the block...well, you may be getting a new boiler sooner than planned.

mr_ius

Nicholas, there were never any main vents put into system. We're contemplating if, where, and how many main vents to put in, in order to get the system working optimally... 2 radiators barley (if at all) work and a couple others don't heat evenly... five radiators come on fairly strong. All radiators have new air vents.

nicholas bonham-carter

I would start with one big mouth on the end of each dry return.
When the boiler stops firing, the steam collapses, and creates a vacuum, which can be quite strong, sucking air noisily into the radiator vents, if no main vents are able to do the job.--NBC

Fred

If, it takes several hours for the water to return to the boiler (assuming it does???) , I would suspect the wet returns may be clogged/partially clogged causing a very slow return. If it were a vacuum, that would be broken in a matter of minutes after the boiler shuts down as a result of the radiator vents opening.
Does the water eventually get back to its original level? If not, look for a leak somewhere in the system.
You do need main vents, but I doubt that is the cause for water taking hours to return to the boiler. I see what looks like a wet spot on the floor, to the right of your last boiler picture. Is that from the boiler? Is that gauge working? If so, the Pressure is high. I would also suggest a 0-3 PSI gauge so that you can actually see what the pressure is.

mr_ius

Fred, yes it's taken basically a day for all of the water to return to the boiler. I thought I'd fixed the flooding problem by installing the new LWCO at the proper level but after running the boiler three times (6 hrs each time) the water feed display said I added 1 gallon and the display water column shows no air (flooded) ... The first time I ran it with the new LWCO I saw it sipped some water once and figured it would be a one time event but now I can see that the LWCO has been activated a number of times. There are no visible leaks. It's possible there one in a crawl space somewhere.

Even if there were a leak it seems like the LWCO adds so little water each time it's activated it would be strange to have taken on so much additional water, unless the activation of the LWCO is having a cumulative effect and being activated more frequently than I'm realizing. My water feeder is on the LWCO setting so I'm assuming it's only adding enough water to reset the float (which maybe adding a 1/2" or 1" to the system at a time ? ) .

Fred

@mr_ius , here's what I would do if that were my boiler:
- Have the boiler, piping, valves and vents inspected for any and all leaks and fix those.
- Have an annual maintenance on the boiler, especially cleaning and adjusting the burner.
- Drain and flush the boiler
- Have the boiler skimmed. The water in that sight glass does not look good at all.
- Have the wet returns flushed out to remove any crud.
- Have the water feeder serviced. They can leak past the solenoid valve even when the boiler/LWCO is not calling for water.
- Have the Pressuretrol tested and re-calibrated if needed.
- Have a 0 - 3 PSI Gauge added to the boiler so you can actually see what the pressure is. Those old 0 - 30 gauges are no good for low pressure steam, even though they are required by local code.
- Have good vents installed at the end of the mains, after the last radiator run-out.

Any water added to the boiler, by the auto feeder is, in fact cumulative so if the condensate is slow to return to the boiler and the LWCO calls for water, the auto feeder will add it and then after the water in those slow returns finally get back to the boiler, the boiler will be over-filled.

dc07736

Having a hard time finding a 0-3 psi gauge.
Any suggestions?

DC

BobC

This is what most of us use.

http://www.valworx.com/product/low-pressure-gauge-25-0-3-psi

Bob

mr_ius

Great, I'm ordering on today !

mr_ius

Any thoughts on where I can aquire the below TRVs? I saw these in Dan's book, "Greening of Steam". Have been trouble finding them.
Thanks !

Sorry if the photos are rotated. Could not get them straightened.