I have put in two underground sprinkler systems that my buddy has designed. Putting a sprinkler system in is as easy as following the instructions for legos when you have a map of where the heads go and the size of pipe for the pressure and G.P.M. that the meter puts out. My friend does it by hand. I was wondering if there is a computer software program that computes friction loss and such, so I can just plug in the pressure, G.P.M., and the dimesions to find out how many heads I can put on a zone.