I purchased a 10-year old house about a year and a half ago... the existing sprinkler system hasn't worked since I moved in and I've started to investigate into how its all laid out. This isn't directly related to why it hasn't worked...but after looking over things I discovered that they tied one zone directly into the main water line without using a backflow preventer or anything. And the other three zones (while tied into a backflow preventer), are located right under a bush. So I am going to need to move all these valves and plumb it correctly so its safe and can be maintained. My question is do you think there are any issues by reusing the valves, or should I just buy new ones since I am going through the trouble of disassembling the pipes, laying new ones, etc.? These are 10-year old rainbird DV valves. I have replaced the diaphragms as part of my repairs. They turn on and off fine, and don't leak as far as I can tell. Have there been any kind of improvements, etc. in the past 10 years that I could benefit from or am I good with what I have?