So one of my apartments (first year contract for me, 15 yr old property) had 135/140 psi at the backflow. Soon as I realized this I immediately put in a request for a pressure regulator. Bid was approved and installed. Prior to this we'd get leaks and breaks that were pretty obvious it was from high PSI water hammer on the lines. Now that the regulator has been in I'm changing out A LOT of formerly working heads. 2 cases of RB 5000s and counting, in just one month. Whats the deal with this? Any body else run into a similar situation? The best I can come up with as to why they were working and now they aren't is from my help. He wondered if the pressure was so high that it forced a lot of sand/grit past the filters and even tho it was gumming up the works the super high pressure kept the heads working. Now that the pressure is back to more manageable levels the heads just won't work. Thoughts????????