Irrigation valves reefsafe?

[Delphinus]

I was thinking more along the lines of what would happen to the metal bits in SW over time, thinking they'd corrode eventually. Also there was something else .. can't remember what part it was, but it was a white plastic with these little tiny holes (sorry can't really describe it). I totally saw it getting encrusted with stuff and not sealing properly. I felt a ball valve would serve a closed loop better but unfortunately an actuated valve seems to be big $$$.