Hi I have a few questions.
1) The pic below is of the outdoor water pipe in my backyard. Inside the basement is a shutoff valve for the outdoor water supply. The red tap is another shutoff for the outdoor water supply. The blue tap is for the garden hose. The hose attachment thread for the garden hose is a bit obscured in the pic. The tubing that goes past the garden hose valve is for the sprinkler supply and it enters the ground.
My question is, as long as of course the shutoff valve in the basement is off and the red tap is closed, can I hookup a compressor to blow out the water from the sprinkler lines? The reason I ask is that when I read the product description for blowout compressor adaptors, it states; "Do not connect to the hose faucet attached to your house". So not sure why?. How would water feed back into the home?
2) During the winter, when the shutoff valve in the basement is off and the red tap is off, is it safe to say, I should not be worried about water freezing in the pipe for the portion of length from the red tap to the bricks?
3) What is this green contraption? it located on the front lawn close to the sidewalk.