I purchased a home four years ago where the owner installed an irrigation system. I noticed the valves were leaking then and replaced four of eight. I figured they were old, and wear and tear took it's toll. Now four years later I replaced the same four again for leaking and found out the owner never put in a pressure regulator. The readings at the street is 90psi, do I need an irrigation pressure regulator? The old valves were 3/4in RainBirds. They were replaced with 3/4in Orbits.
Update: Sounds like your irritation is fed from the main spigot that is before the house pressure reducer valve, in which case 90psi is normal but may be too much for some irrigation systems. Depends on how the system was designed and how the pressure is diversified. You could easily put on a pressure reducer and see if that helps while still maintaining good overall pressure.