the association sprinkler system dont work any more so i want to setup my own sprinkler system feeding from the outside standpip, not interested in pump, what do i need i'm only using about 7 to 8 sprinkler head, i know how to glue the pipe and add the sprinlker but that's about it i repair sprinkler before but i never start one from scratch

what size pipe to used

i know i need a back flow valve

what else do i need put them together

i know i will need electrical current which i know how to connect

i estimated i will need about 14-15 length of pipe