Okay, I admit it--I'm obsessed!

bobbob

Have old one-pipe coal converted to NG Crane 20 Boiler. 12 radiators. Big Brick house. Been here 21 years, and felt it was time to give my system some attention. Bought "the Lost Art..." when we first got this house. Discovered HH.com just recently.
Always kept water clear, but other than that, have not done any fixing, and it has not needed any. The system works well. I replaced 8 rad vents, finally got it through my thick skull that I needed to insulate (20% of pipes were bare, half of the rest had insulation that was two sizes too big in diameter), so I just about have that job completed. System only had one main vent--Hoffman 75--but it was located about 4 feet from the header, so it has likely been just an ornament. Couldn't have done alot of good. Am getting ready to add main vents. Will have to drill pipes and weld on nipples as I feel it would not be wise to try to disassemble these old pipes to add tees. Here is where I need advice:

My system's steam mains loop around the basement area, and are all interconnected, therefore making a "loop." I have not seen anything like it on HH or in Dan's book. I assume I should place vents in spots where I drew STARS on the diagram. Is this a rare setup, a boondoggle or what? As I stated, my system works well, all rads are getting close to totally hot, no hammering. Don't want to do something that might upset that.
Thanks for input!

Steamhead

That main should pitch down as it gets further away from the boiler. Where is the highest point and where is the lowest point? How long is the main? What pipe size?

bobbob

Steamhead--I know my diagram may need some explaining. The arrows drawn along the main piping shows the direction the flow goes. It does not seem to pitch as steeply as it should be, but I don't know of any way to correct that. The mains are 1-1/2" and the runouts to the radiators are 1-1/4". The long run of the main on the south side is 28 feet. It appears to my untrained mind that from the SE corner the condensate runs West back to the left side of the boiler header, and from the SE corner condensate runs N and W back to the short "return" into the boiler. I hope you can make out the Stars I drew as places where
vents might be best placed. As seen in the diagram, the runout to the upstairs bathroom is a very long span, so I thought it good to vent it just before it heads upward. Alternately, I could put a vent at the rad's valve as I have seen done on utube.

Steamhead

Might want to check this with a level, if you haven't already. Also, where are you located?

delcrossv

Are you saying both ends of the loop are connected to the steam supply?

EBEBRATT-Ed

You only show 1 return unless something comes back into the header counterflow your arrows are not making sense. You need to take a level and figure out how steam gets to the radiators and how the water gets back to the boiler

bobbob

In W. Central Illinois. I have checked with a level, and yes, it is like I show in my diagram. It does not seem to make sense to me--though I know almost nothing--and sounds like it does not make sense to you who have responded.

Is it normal to have condensate return to the boiler through the header? It would appear that it does on the west side. On the east side it has what I think may be termed as a wet return, which tees off from the main down to what I assume is the hartford loop. So, yes both sides of the mains return condensate back to the boiler.
As I stated, it has worked well for the 21 years we have owned this place. I just recently cleaned the pigtails and sight glass and valves and replaced 8 vents on rads which heated up only 1/3 or 1/2. I have always kept the water clean. All 12 rads now heat up fully or near fully. Also changed to a thermostat with adjustable "swing" because it seemed to be short-cycling somewhat with the electronic one I installed last season. Should have kept the mercury Honeywell.

bobbob

P.S. My goal is to get my system operating at maximum economy. I have only recently learned how important insulating and main venting is.

delcrossv

OK, looks like 2 counterflow mains hooked together in a loop. also looks like the high point is in the corner opposite "kiddycorner" to the boiler (lower right on the diagram).

The way I see it, your vents should be in that lower right corner farthest away from the boiler that's the high point.
Also, the main to the left of the boiler should have a condensate drip to match the one on the right.

The pros may have different comments. If it's working fine now, why mess with success? Insulate and call it a day.

bobbob

delcrossv--You are correct about the highest point. Your idea of adding another condensate drip on the west side is well taken. I will do some inspecting to see if that is feasible, which I think it is.
I also don't see why the piping in the SE corner could not be eliminated (between the front LR riser and the Middle LR/office riser) since the condensate flow goes opposite directions from that corner.

It would be a major operation to attempt changing the pitch of anything because the mains run through brick walls in several places.

Mr. Holihan strongly stresses the need for plenty of main venting, and that is why I am concerned about adding some vents. In my thinking it would help get the heat to the rads quicker, thereby shortening the boiler run time and saving $$$.

I welcome any more thoughts on all this. Thanks!

Steamhead

I'd put all your venting at the southeast corner, since that is the furthest point from the boiler.

bobbob

I just got back up from my basement. I looked over my system and discovered there IS a condensate drip on the west side as well as the east side. It is as plain as day to me now and the pitch of the pipes makes sense. Boy, do I feel dumb...

bobbob

Oh, and thanks to all you guys for your help. I love it when I see folks helping out others folks. You are good "neighbors."