My supply to my sprinkler system is 3/4"...what size PVB should I install 1" or 3/4"...is there any advantage to 1"...also, should I sweat it in, or install a PVB with unons?
no advantage in upsizing the PVB, since they are flow-rated like water meters are, and capable of handling flows way beyond what your sprinkler system would use