Hi all- I have a problem which I think is not too complex but tedious. I have a centifugal pump which is has a expansion tank on the suction side and a boiler on the discharge side. I would like to get a system curve so I may then select a suitable pump. The problem I am having is the system starts out as a 3" to 2.5" to 2" to 2.5" to 3". Then to even complicate things further there are 16 1" branches which feed radiators. Does anyone have any suggestions on how I can accratly model this system.

Neil MacLeod neil.macleod@gov.nb.ca

(1). Looks like that you have a dragon and two octopus in your system. I can't get a clear picture. (2). But, I think you are dealing with the loss in a pipe system. So, try to find some empirical formula to compute the loss in pipe as a function of mass flow rate.