Irrigation Winterizing help

[Nicolas]

Hello, This year for the first time I was tasked to winterize my house's irrigation system. Knowing close to nothing about it, I spent the last few days doing some research about how to do the job. Oddly enough, I couldn't find a single system identical to mine, or even similar. It seems that I have no valve to plug in the air compressor and that there is no backflow preventer, just a shut-off valve in the basement. Is there an adapter I could plug in the pipe in the upper right on the first picture maybe? If not, what do you guys suggest?
Thank you (and sorry if these things are supposed to be basic knowledge...)

 

[Gary Swart]

The system must be blown out to get all of the water out. This requires a large air compressor, so the normal way to winterize the system is to hire this done. It is not a DIY job for most of us because to the size of the compressor needed. The lawn mowing service companies undoubtedly are in the process right now of blowing out systems. They rent the big industrial compressors and will make short work of the job.