I have a lot of customers in one water district, that over the last year replaced all the water meters. Just before all the meters there is now a dual check valve (not a double check). And many of the PRVs were replaced as well. I'm finding many of these systems do not work properly now, as the new equipment must be restricting volume/flow more than the originals. One in particular yesterday had four impact heads per zone, and many of them now stick in one position, and don't throw the way they used to. This particular one may also have a PRV problem though. When they replaced it they turned the screw all the way down for max pressure. I have found many PRVs adjusted this way, and something (plate/spring) inside ends up blocking the flow/volume. So she has around 85-90 psi at the RP, with a 1" main into the house, and out to the sprinklers, yet the system now works like crap. The only thing I could do was to change out the impacts to gear drive rotors. Had to mix and match the zone. She was so worried about it burning up because they wouldn't operate. PRV is before the meter so I can't replace it. and I know talking with the district will get me no where. Had it happen last year on another one where they kept telling me that the pressure was great, which it was, but they didn't get the concept of volume. So we went round and round and they finally did what I told them it needed, and then it worked great. I guess my main gripe is that they are going to tell me that I don't know what I'm talking about and won't fix the problem. This isn't the only house that I'm now having problems with in the area. I may get a bunch of redesigns to do later from this.