A few of my neighbors came by to talk to me while I was outside working on my sprinkler valves and manifold at my house. They mentioned our town recently sent them letters stating they need to have a Backflow Preventer installed on their sprinkler main if they haven't already, which they have not. I don't know why we haven't received this letter, but I thought it would be wise for me to deal with it now while everything is dug up. Like them, our system has never had a backflow preventer, so I'd like to add it now rather than being told to do it later on. This system does not have a MV, just a spinkler water main shut-off valve in the basement, which is 1" copper that is run to my 11 zone manifold. I really don't know exactly what to purchase and prices also seem to vary greatly for this part, not to mention there are single check valve type, double check valve, and pneumatic. Anyone have any suggestions? Thanks.