How Much Pitch . . .

EasilyFound

Also found this in Dan's book, which seems to apply to my situation:

"If the riser feeds just one radiator on the second floor, and you haven't dripped the base of the riser, the pitch of the horizontal run-out must be at least one-half inch per foot and one size larger than normal."

The horizontal run-out pipe I'm talking about is about 7 feet long. I've also noticed that the riser in my 2nd floor apt is thicker on the lower floor than the two higher floors, so that suggests that the pipe is one size larger than normal. I guess it needs about 3.5" of pitch. I don't know if I have that much room underneath the floor to give it that much pitch.

EasilyFound

Question About Pitching Steam Pipe

I see on this site and in Dan's book that the amount of pitch for the main in a counter-flow system is one inch in ten feet. That means, I presume, one inch for every ten feet of pipe. So a twenty-foot pipe would need to be pitched two inches. And does this rule (one inch in ten feet) also apply to a horizontal offset pipe connecting one riser to another?

EasilyFound

Maybe I found the answer, but I just need to be sure I'm using the right terminology. I found this info on this site:

"The exception to this is when you have a horizontal run-out to a radiator riser. Here, the pitch should be at least one-inch inch per foot. Where you can't get this pitch, (or when the horizontal run-out is longer than eight feet) you have to go to the next-size pipe."

I think the pipe I'm concerned about is a horizontal run-out. The main feeds a riser that feeds a radiator on the first floor. The riser continues up to the second floor, but must travel horizontally under the second floor to feed radiators on the second floor and then it connects to a riser that feeds radiators on the third and fourth floor. The horizontal pipe I'm talking about is that a horizontal run-off? Or is it called something else?