is this the new poly vs. pvc debate?? to MV or not to MV that be the question.
recanting my previous statement, master valves are more of a pain in the butt than they are helpful. they mask all leaks, be it large or small, and during a manual service inspection require a manual opening, which then requires me remembering to manually close. which i usually dont remember to do till im on my way home for the day, thus negating any beneficial quality of said master valve.
my new position, master valves only belong with flow sensors and smarter controllers. all other installations are poppycock.