Sprinkler system backflow

Does anyone have to do a back flow on their sprinkler system when they close it? Who do you call to do it? Thanks!

Re: Sprinkler system backflow

do you mean a blow out, all the sprinkler lines are blown out with air to get all the water out so nothing freezes over the winter?? If that is what you mean, any sprinkler company can do it or if you have an air compressor, you can do it your self!