I need to replace valves in a 6 zone system. the system is piped with 3/4 PVC pipe and has some sharp 90's right out of the valves. What are best valves and valve sizes to use considering I have 3/4 pipe. Should I use 1 inch vavles and reduce? SHould I go back with all PVC although this may require 6 union fittings or can I switch at vavles to a differnet kind of pipe
