Thanks, Dave, that looks real interesting. Today I had a long phone conversation with the engineer who designed this nozzle package. The most important thing I learned was how little I know about the use of regulators on a nozzle package. Once I specify the gpm, that it what flows through the nozzles, regardless of the system pressure. Finding the right balance on the pump curve can be a little tricky when you don't have a pump curve. Trial and error varying of the discharge to arrive at the desired pressure should give us a flow rate if we had a flow meter. Now I need to find a good cheap source for an 8" McCrometer. Thanks again for the link/advice. Gary |