Replacement Steam Boiler

jjheat

I have an existing boiler that the 2- 4" steam supplies tie directly into the main steam piping that feeds the system with no header due to height restrictions. I have searched all the different manufacturers for the lowest water level in the boiler to be able to put a header. There is no boiler that will be low enough to maintain the dimensions in order to accommodate a header. Do I tie in directly to the distribution piping like the last boiler did? From the floor to the center line of the distribution piping is only 67".

Dave0176

67" inches isn't too bad Weil McLain and Peerless boilers are around 32" in height. You run your risers as high as possible then drop as low as you need into a drop header as long as you stay above the top of the boiler. Well I just realized that you have a large system, but even a Weil McLain 80 series is 47" at the top with a 32" water line, you can still use a drop header.

jjheat

Burnham 5 series water level is 30". I need to pour a pad for the boiler, as the floor is in bad shape and basement has water issues so add 4" for slab so thats 34" water line now add 24" to bottom of header plus a 6" header I am at 65" to top of header not leaving only 2" to tie in off the top of the header.

KC_Jones

As Dave said you need to do a drop header. Look at the picture on my profile. That is a dropped header. Risers go up then back down into header. This is a common method used when there isn't much headroom.

Jamie Hall

And be very cautious about lowering the water line from the existing installation. You must NOT change that water line either up or down more than an inch or two -- or be prepared to do some significant troubleshooting and repiping of lines out in the system, to maintain proper water seal elevations.

jjheat

Thanks KC. Is your drop header 24" above the NWL or it doesnt matter due to the risers being so high out of the boiler??

KC_Jones

The header position on a drop header isn't critical, other than staying above the top of the boiler. Go up as high as you can with riser then back down as far as you need to make the main connections.

ChrisJ

Jamie Hall said:

And be very cautious about lowering the water line from the existing installation. You must NOT change that water line either up or down more than an inch or two -- or be prepared to do some significant troubleshooting and repiping of lines out in the system, to maintain proper water seal elevations.

Jamie,
I'm not sure I agree with this statement. Many systems, including mine would have no issue with this. I could lower my water level as much as I want and raise it a good foot before I'd be concerned.

I have to think it depends greatly on the system and anyone replacing a steam boiler needs to evaluate the entire system to see if it's a problem.

vaporvac

Well, at least the wet returns need to stay wet.

ChrisJ

vaporvac said:

Well, at least the wet returns need to stay wet.

Or dry and draining well, no in between.

jjheat

Only dropping the water line by 3-4". Wet returns. 1 pipe steam.
KC thanks. The boiler risers should come up as high as I can but stay below my distribution piping correct? That will give me about 2' pieces out of the boiler and about 38" above NWL.

ChrisJ

The risers can go as high as you want, even above the steam mains.

Then drop down into a header.

Jamie Hall

ChrisJ said:

Jamie Hall said:

And be very cautious about lowering the water line from the existing installation. You must NOT change that water line either up or down more than an inch or two -- or be prepared to do some significant troubleshooting and repiping of lines out in the system, to maintain proper water seal elevations.

Jamie,
I'm not sure I agree with this statement. Many systems, including mine would have no issue with this. I could lower my water level as much as I want and raise it a good foot before I'd be concerned.

I have to think it depends greatly on the system and anyone replacing a steam boiler needs to evaluate the entire system to see if it's a problem.

As a more general statement, you are right . There are many systems where it doesn't matter at all. There are other systems, though, where the wet returns may rise quite a bit as they go out in the system, and where lowering the water line may just allow the ends to dry. If there is supposed to be a water seal out there, and one dries it out... trouble.

I think I use that statement as a good general rule -- to which there are always exceptions but which can be evaluated by someone who really knows what they are doing!

ChrisJ

Jamie Hall said:

ChrisJ said:

Jamie Hall said:

And be very cautious about lowering the water line from the existing installation. You must NOT change that water line either up or down more than an inch or two -- or be prepared to do some significant troubleshooting and repiping of lines out in the system, to maintain proper water seal elevations.

Jamie,
I'm not sure I agree with this statement. Many systems, including mine would have no issue with this. I could lower my water level as much as I want and raise it a good foot before I'd be concerned.

I have to think it depends greatly on the system and anyone replacing a steam boiler needs to evaluate the entire system to see if it's a problem.

As a more general statement, you are right . There are many systems where it doesn't matter at all. There are other systems, though, where the wet returns may rise quite a bit as they go out in the system, and where lowering the water line may just allow the ends to dry. If there is supposed to be a water seal out there, and one dries it out... trouble.

I think I use that statement as a good general rule -- to which there are always exceptions but which can be evaluated by someone who really knows what they are doing!

I've got no problem with that.

You saying it, and me commenting on it likely will make the OP consider it as well as many others down the road.

That's a good thing.