Looked at an ADSCO system....

Jim Bennett

last weekend. A friend bought a house that was vacant and unheated for a couple of years. Luckily, the steam boiler was drained and there was no freeze (Western NY) damage to it or the system.



I work for a commercial/industrial plumbing Co. I do steam piping, but not residential. I love reading about these ancient steam systems here, but never get to see any other than the pics posted here. Needless to say I jumped at the chance to see one in person.



I found what turns out to be an ADSCO atmospheric vapor system that has had a bit of knucklehead added over the years. It is a two pipe system. One return main had a  vent that has been capped, the other has a non working vent. All the radiators have vents added to them.



Questions: I do not believe from what I have read that the radiators should be vented. They where added because the rads did not heat because of the vent issues on the return mains. Does it do any harm to leave them?



I have also read that these systems used to vent through a pipe through the roof, or alternatively into the chimney. What is the preferred method today? Should I pipe it back the way it was or just add main vents to the return mains?



I also need to replace the pressuretrol with a vaporstat. and address a few radiators that have had their orifice valves replaced with non orifice ones.



Am I on the right track?

Steamhead

That version of the ADSCO

may not have vented thru the roof or chimney. If it did, you'd probably find where the old vent pipe was.



The easiest things to do now are to vent the steam mains and dry returns, and remove the radiator vents and plug their holes. Measure the lengths and diameters of the steam mains and we can tell you what you need. If the steam mains are not vented now, drilling and tapping the pipe is the easiest way to vent them.



If this system does not have traps on the radiator return connections, it's probably an Orifice type. This makes the Vaporstat a must, as the pressure must be kept low.

Jim Bennett

Thanks Frank....

I plan to look closer in the boiler room when I return this weekend. It has about 100 feet of two inch steam mains. One 45 feet, one 57 feet that loop around the basement and tee together. They are connected in the middle to the dry returns through a loop seal.



At one time here on "The Wall" I think someone posted an orifice chart for determining orifice size per Rad EDR. Do you know where I can find that? I still have to deal with some non orifice rad valves.



I want to get this system running the way it should. I already talked him down from the steam to hot water conversion. This is a nice old house that was probably one owner and kept in great shape until a few years ago.



Jim

ttekushan_3

AO barnes & Jones

Hi Frank,



I think you have mentioned in the past that the Barnes & Jones Adjustable Orifice Radiator Valves are pretty good. They have an adjustable stop (adjusted with a skinny screwdriver in the stem). I'm considering them for upgrading a vapor system addition rather than using orifices.



Would they work here as well? They only come in 3/4" and 1/2."



-Terry



P.S. I have 140edr out of the 200edr of the steam addition running, soon to be finished. (It is replacing forced air that's noisy and has no cold air returns near the floor. The bottom 8" of the room fills up with frigid air whenever a door is opened. Its a two storey addition of about 850 Square feet down and 500 up).



Cast iron column radiators that are identical to the ones in the main house were a nice find. The steam radiant in the kitchen is working out exceptionally well so far, with no overheating of floor surfaces. I'll post pictures when completed. I'm pleased it is running silently and evenly on 3 oz steam pressure.

Steamhead

Don't see why not

MEPCO (formerly Dunham) makes them too.



Pics! We need pics!



Not sure about that orifice chart, JK, but I'll look around and see if I have a copy.

Unknown

Radiator Orifices

Unfortunately my link to the orifice chart on the old board apparently doesn't work anymore. You might ask Dan for it. It was in the old library.

Here are a couple of links I've saved on orifices that might be helpful to you:

 Tunstall has orifices available. 

 http://www.tunstall-inc.com/tunstallsteam.html



Barnes and Jones -  They have adjustable orifice valves http://www.barnesandjones.com/index.html



Henry Gifford- He has an article on orifices which shows an orifice chart.

Got to the link below and go down his main page to  "The Technical Information Section" and then to "Two Pipe steam Heating Systems" and click on the link "Orifices Article" 

 http://www.energysavingscience.com/



- Rod

Jim Bennett

Thanks Guys....

I read the orifice system article. That chart will do the job! From what I have read about ADSCO systems, the radiators are sized 20 percent larger than what is needed for each room. Then the valves are sized to only allow enough steam vapor in to fill 80 percent of the radiator at 5 oz of pressure. This keeps steam out of the dry return.



I will replace the main vents and rad orifices. Lose the radiator vents and test. Last week it took an hour + to get the radiators hot.



I'll let you know how it turns out.



Thanks again.



Jim