I had a sprinkler specialist come over today to winterize my sprinkler system. I live in northwestern oregon (portland) and I'm trying to figure out if he properly winterized the system or if I need more to be done to ensure I don't have a freeze split open a pipe. Most everything I've been researching online has advised blowing out sprinklers systems.
A bit about my setup: I have 8 sprinkler valves (3 sprinkler valves, 5 drip valves). Part of the system is in the front yard and backyard. The backyard slopes downward slightly.
Here were the steps he did:
Turn valve (1) to closed position
Unscrew cap on test port (3) (i.e. port closest to where water flow exits the backflow preventer)
Used mini screwdriver to open up ball valve on test port (3) until some water stopped draining out. This was very little water that drained out, likely less than a cup.
Use screwdriver to close ball valve on test port (3)