Our back yard lawn sprinklers make a loud banging sound whenever they shut off. It's been this way since we bought the house four years ago, but I just now got around to investigating. I now realize that we are experiencing severe water hammer. There are eight sprinkler heads on one anti-siphon valve (too many?). I tried reducing the flow, but to significantly reduce the hammer, the flow had to be so low that the lawn was not being watered properly.
I did some research and found some Hunter valves (type HPV) that claim to close slowly to eliminate water hammer. Do these work? Any other suggestions (other than digging up the lawn to add zones)?