The
Toro P-220 or the
Hunter Pressure Regulator in combination with a Hunter PGV valve would work. You could also consider installing an adjustable pressure regulator before the backflow at a lower cost, you would lose any adjustability per zone, however.
Click the valve name for the link.
Take the readings you get at the backflow and subtract 5 psi. This will take into acct. the valves pressure loss and any loss from pipe friction. Taking the reading at the head would give you your most accurate readings, though, but this is difficult to do. Most Tech's would calculate pressure losses based on flow and zone layout.
15 gpm through 1" PE pipe is not the end of the world, though. It's 1 gpm higher than what is recommended velocity. If you're concerned with velocities, limit your flow. What I don't know is if a pressure regulator would do that for you.
This post has been edited 1 times, last edit by "Central Irrigation" (Apr 29th 2012, 5:21pm)