I'm not sure if this is the right category to post this so here goes. Long story short I am getting ready to install my backflow preventer, Zurn 34-720A Wilkins Pressure Vacuum, on my DIY irrigation system. The main water supply is the pipe coming out from under the storage shed. It tees off to the left for the water hose bib and the irrigation is on the right. The other two PVC pipes in the pictures go out to the yard irrigation. The second picture is a mockup of my plan. My question is should I move the water hose bib to the down leg (the outlet side) of the backflow preventer as demonstrated in the third picture? That way the water hose bib will be protected by the backflow preventer and the backflow will be installed 12 inches above the hose bib. You'll have to excuse the bad photoshop lol I attached pictures.
Do whatever the county official or water company recommends. Back flow from the spigot should not need protection so as long as the irrigation system cannot flow back to the water source you should be fine.