Updated ADSCO to DONNELLY system

Kevin_37

Thank you Steamhead for your response thus far. I will draw a mental picture of the steam layout using up, down, north, south, east and west. Here goes:
The boiler has one 3" supply.
AT the boiler is a 3 to 4" short (2" long) adapter.
A 4" riser 24" comes up to one of the thru ends of a 4" tee.
On the other (top) thru end it is bushed down to 1 1/4 and has a Conbraco pressure relief valve at 15lbs. On the odd (horizontal) leg of the tee starts the header 4" x 24" north to another 4" tee at a thru end. It comes out the other thru end then runs 12" to a 4 x 2" elbow turned down to make the equalizer. At the odd leg of tee it runs east 30" to a 4" elbow turning south and runs 15.5' to the odd 4" inlet side of a 3x3x4" tee. Yes its bullheaded. This is where the main splits to run east and west to each side of the building then north down each side. I'll describe the east leg first then the west leg. At the east 3" outlet side of the 3x3x4 tee 3" main runs east 11' turns south 5' then east 15' and finally north 42' to its end where it reduces to 1 1/4 and drops thru a water seal to the dry return. At the west 3" outlet of the 3x3x4' tee the 3" main runs west 5' turns north runs 45' turns east thru a reducing 3x2 1/2" elbow then the 2 1/2" main runs 29' to its end and turns down reducing to 1 1/4" thru water seal to the dry main.

I used the table in The Lost Art of Steam Heat" to staighten out the runs. When in doubt I used the higher figure as in the 3x3x4" tee. I came up with 78' of 4" main, 101 feet of 3" on the east leg and 65 feet of 3" on the west leg and 35 feet of 2 1/2" at its end.

I hope this is clear. Thanks is advance for your review and advise. Kevin

Kevin_37

Updated ADSCO to DONNELLY system

I inherited a two pipe ADSCO system when I puechased an apartment building five years ago. I believe it to be an old ADSCO because I found the ADSCO union elbows on the return side of radiators and slotted disks at the radiator supply valves. I also found one pipe air vents on some of the radiators. This building has 10 units and approximately 24 radiators. The boiler is a current model Smith GB300-6. It had a condensate return pump. And it had $1200.00 dollar a month gas bills. The system starts with a four inch main for about 14 feet then bullheads to two three inch mains that run down each side of the building. Reducing to 1 and 1/2 inch they approach on the opposite end of the building. They drop thru a drip loop to the dry returns just after the last radiator on each run. They join into a two inch dry return that lead to a bucket trap then a disfunctional condensate return pump(old "Watchman"). Then it was pushed thru a 1 and 1/4 inch swing check valve and back into the TOP!? of the boiler. The boiler was controlled with a thermostat, a mechanical pressuretrol and mercury high limit pressuretrol. The mains had no vents just plugs where they might have been and no insulation. Then came "The Lost Art of Steam Heat". In an effort to simplify and gain control of this system I insulated the mains. Then I removed the bucket trap and condensate return pump and replumbed the returns just after the last radiator together into a 2 inch dry return with proper grade to the boiler. There I dripped it thru a hartford loop to the equalizer I installed on the boiler. I removed all the metering disks, the union elbows, and the one pipe vents at the radiators and installed Turnstall EC3 steam traps. I installed Hoffman 4a quick vents just back from the end of each main up on risers. I installed a Vaporstat and a one to five pound gauge with tenth of a pound increments. I also installed a Paxton controller, which senses outdoor temp, indoor temp, and boiler water temp to call for heat a certian number of minutes and times each hour. The system now resembles figure 61 on page 269 (the Donnelly system)of the fourteenth printing (special Anniversary Edition) of "The Lost Art of Steam Heat". However there is no vent on the dry return, the check valve at the boiler on the return is a hartford loop and the check valves on the radiator are steam traps. I am currently cutting in at about 9 ounces and out at about 19 ounces. The system appears to work well. I have a few concerns. Did I use the right vents on the mains and should there also be one at the end of the dry return just before it drops thru the drip to the hartford loop at the boiler? When the system shuts off it pulls a couple of pounds of vacuum for a while. Should this system work theoretically. I am a little to close to the subject now so a second opinion is worth while. My last update will be to install Thermostatic supply valves as funds permit. Any thoughts?

Steamhead (in transit)

Those 4A vents are almost certainly too small

measure the length and diameter of the steam mains- you say they reduce in size, need to know how much of each pipe size is in each main. Then we can size your main vents properly.

You do need a vent on the dry return, placed so it can vent the air coming back from all the radiators. A Gorton #2 should be fine. This would let you reduce the pressure even further and save more fuel.

Essentially what you've done is go from Orifice Vapor to standard Vapor with traps. The traps are additional moving parts, but should last a while if you keep the pressure down.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Kevin_37

Main size and lengths

> measure the length and diameter of the steam

> mains- you say they reduce in size, need to know

> how much of each pipe size is in each main. Then

> we can size your main vents properly.

>

> You do

> need a vent on the dry return, placed so it can

> vent the air coming back from all the radiators.

> A Gorton #2 should be fine. This would let you

> reduce the pressure even further and save more

> fuel.

>

> Essentially what you've done is go from

> Orifice Vapor to standard Vapor with traps. The

> traps are additional moving parts, but should

> last a while if you keep the pressure down.

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 367&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_

Steamhead (in transit)

Use

two Gorton #2 vents at the end of each main. If you can't find Gortons in your area, call Ken Kunz at Gorton, 908-276-1323 and he will see that you get them.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Kevin_37

Thanks for your input. I found a company online to order from, "Pexsupply.com" per the good folks at Gorton. I guess I'll need a total of three (one for the dry return). I stuck an old Hoffman #43 on the return (till the Gortons get here) and set my cutin and cutout at 4 and 8 ounce respectively and we are getting plenty of heat.
Thanks again for the help, Kevin.

Steamhead (in transit)

That's why we're here, Kevin

let us know how well it works with the Gortons. You'll see a big difference!

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"