| Re: question about pipe size Hi Jon, If your house has 1 1/4" mains you will stub out 1" from a line supplied from the main with no branches into a Sloan# 115 polished chrome flush valve. Most houses do not have a 1 1/4" main so They stub out 3/4" and will connect into a Sloan #186 . The top spud is the connection locatred on top of the urinial. The drop pipe from the flush valve connects into that. More questions? Click on back. Good luck, Tom |