I get a decent amount of water hammer in the garage were the main sprinkler line is tapped off the 3/4" entrance to the house (before the PRV). I know the way water hammer works and I know in my case it is caused because my Rain Bird valves are slamming closed and the water is at a high velocity going through them. That sudden shutting action causes the water to "hammer" to a stop thus vibrating the pipes. Does any company make slow closing valves? (my Rain Bird valves are simple open/close valves) I need a modulating type that will slowly close preventing hammer, thanks.