shrinking steam pipes?

tom_82

Will steam pipes(mains) build up residue and sludge, reducing the inside diameter of the pipe, and limit the flow of steam over the years?
If so, would the solution to this be to have air vents at the end of the mains constantly pushing through steam in order to keep the lines filled with steam so that the far end rads get hot?
This is what I was told.
Oh, It's a one pipe parallel, up feed (three floors) steam system, without bleeders at the risers. I havn't measured yet but if I had to guess I would say the mains are about 120 feet, more or less.

Thanks,
TOm

brucewo1b

Tom

think of it this way the staem mains are getting cleaned on evey cycle, however the crud flushes into the returns and builds up there and therefor the returns should be flushed yearly to keep them clean. Yes vents should be near the ends of the mains after the last upriser butv 15 inches before the drop back down. If you can give us the size and lenght someone here can tell you how many of what main vents are needed on each.