one pipe steam

SC

I have a four story building. The boiler is in the rear of the house, the 2" main in the basement runs about 80' to the front of the house. The radiators in the front of the house are not getting as hot as they should, however, the risers do get hot. There were no main vents on the basement 2" main so I installed four #1 at the end of the main and three # 1 about 20 feet before the end of the main. The pipe were not insulated so I insulated them with 1" fiberglass. I have change the radiator vents (gorton D)on the first and second for which had a little difference. Should I drill into the vertical riser and install vents? If so, how many? What size? Thanks, SC

ttekushan_3

how about

downsizing the vents a bit on the radiators closest to the boiler room? Also make sure small radiators have small vents. Don't forget that while a vent is open, it affects steam distribution no matter how small the radiator is.

If the boiler's pickup factor is not large enough to supply the volume of steam necessary to assure even distribution with all the new main venting, its possible that your system is overvented. If ALL the vents are large, then you can lose the ability to proportionally vent the system. If there is virtually no pressure at the boiler during the beginning of the cycle, you can afford to do a bit of downsizing of the radiator vents close to the boiler and on smaller radiators.

If you really find that you need more venting on the riser, I wouldn't care to drill it. Go to the radiator at the end (top) of that riser and put a nice vent there. How? By removing the radiator's angle globe valve and replacing it with a Tee. The vent goes on top. The side outlet of the tee then goes to a short nipple, a full port valve, union and nipple into the radiator. The radiator will find itself shifted a few inches away from the riser when completed. Works like a charm.

-Terry

P.S. You've done everything right so far-- you're almost there.