This discussion seems interesting.
Steve,
Our practice in large projects is to use an Combination AIR relief Vacuum/release valve in the high points along the mainline run.
and a pressure reducing valve in the pump room..
I remember that when I used to choose the Pressure reducing valve from the irrigation manager some manufacturer list the pressure relief valve , you may check Netafim(They have Quick relief valve. Not sure if this is the same you are looking for).
I would like to ask please about the difference between the pressure reducing valve and the pressure relief valve and there is pressure regulating valve In term of dealing with surge.
In our projects , we are always asked about surge protection, and we are considering the ARV and pressure reducing valve one of the potential practices.
Am happy to hear your experience toward improving practice in our future projects.
Nibal