Hi folks, I want to DIY a pressurized blow out of my irrigation lines to winterize. It's tougher than the YouTube videos show for me, because my source of water to my irrigation isn't in the basement or crawl. I have a separate line from the city main (and separate bill in fact). All I have access to is the shut-off valve there. So how to blow it out?

I had to repair a valve this weekend and used some schedule 40 PVC on the source side. I put in a fitting that has an exit (currently with a screw topper in it). Can I put pressurized air in there to blow out my six zones? It's on the source side, about six inches from one of the first zone valves. I'm guessing that when pressurized, it should exit water past all valves. I realize I'll still have some residual between the main and the valves that stays in there, but typically in my system that is deeper and more protected. Please comment if I'm misguided!