Very informative for relieving the pressure in a backflow preventer device (RPZ) for winterizing in Texas. Now I know exactly what to do. I had my sprinkler system installed about 4 months ago and the RPZ is exactly as pictured in this video. Many of the other videos on RU-vid had older backflow systems that didn't look like mine. This video made it easy for me to know exactly what to do, so I don't have to pay someone and winterize it. Many thanks!!!😃
The shut-off valves are ball valves. When they are fully open or closed water can get trapped in them. When they freeze this can cause them to break. By putting them at a 45° angle you allow space for water to expand when it freezes, reducing the chance of them breaking.