contractor

67drod

This 4-story building has balancing issue on an vintage 1-pipe down feed steam system, neighboring Cleveland Ohio.  The return lines were replaced maybe 35 - 40 years ago.  We ran clean water through them and the bottom end appears normal.  The main supply has not been located yet.  Infra red will locate the drops but not the main.  The radiators all have thermostatically controlled vents (Macon brand). Some maybe taken off ( in the lower levels) and all are probably set on the highest set point at the top floors.  Observed during these coldest days, the boiler runs 24 hours straight at 2 plus pounds (give or take).  The water meter hardly adds any new water. 4th floor drops are 215 degrees and lowest level is averaged out 95 degrees.    

Under the main vertical riser tee a 1 1/2" pipe  is capped.  Where as at a clone building it is connected back to boiler piping.  20-25 year old boiler header was not completely insulated, all fittings were omitted.  The clone building has nothing insulated.  All 8 vents in basement are relatively new ( with no signs of residue)  on dry returns.  Do not know if there is a main line vent at top. 

  

Steamhead

Call Gerry Gill

He's one of the best. Info here:



http://www.heatinghelp.com/professional/88/G-W-Gill-Plumbing-Heating

nicholas bonham-carter

How about a simple layout drw?

I'm not sure why the main supply is hard to find. Is there only one main vertical feed, which branches off in the attic or top floor to feed those top rads, and then drop down and feed each lower floor in turn?

Often a big main vent, or open trap works wonders at the top of the feed. Considering the combined total volume of the horizontal, and vertical supplies, this system would need substantial main venting.

I am also not quite understanding how the boiler can be running nonstop at 2psi, without any cycling.

How does the condensate get back from the clone building. You may have to get the main building balanced/vented first, with the evil twin building valved off, and then do the clone.

Just as in real estate, the mantra is "location-location-location"; in one pipe steam it is "aspiration-aspiration-aspiration". When the air cannot be easily allowed to escape, the steam has a hard time coming in.--NBC

67drod

4-story down feed 1-pipe steam

Thank you for your recent input.  Explaining this possibly clearer, we are speaking about 2- separate systems in identical buildings.  Bldg. A has issues and bldg. B does not. They both have the same boilers, identical BTU rating and both run non stop at 0 degrees and below.  This was not physically observed, only by the data from the #279 Tekmar controller.   

Bldg. A .... one vertical main riser in the rear of building.  Has no drip leg at its base, has insulated pipes but fittings are not.  The entire space above the top floor ceiling was not available to locate the main horizontal.  Checked in only 1 of 6 units and that was at the furthest distance from the boiler.  Hoffman  Specialty Co. typical drawings do show a main line vent 12 to 18"  near end of the horizontal.  

I believe the dead men knew better than to conceal a problem for anyone ever to raise a voice that would wake them from their peace.  As we offer them a humble offering with our thanks and gratitude, a job well done, Amen.