Originally Posted by MR.M
Very few systems are installed with self draining valves and most of the ones that are designed that way are not installed correctly. Blowing out systems is a Necessity in most cases. Using 150psi is not 40 will do just fine . Even good self draining system can leave enough water in the valves to damage them . Though sprinkler systems can tolerate some water freezing in the lines and will not damage the n in a RV it.s a different story . RV get blown out and then pumped with glycol . Why chance it !
When I lived in Colorado and wanted to have a sprinkler system installed I found I needed to study a foreign language first, just so I could communicate with the "contractor" to get a quote.
I decided to design and install myself. Price was great and everything worked just the way it was supposed to. Like I said earlier, it helped that all my sprinkler runs were on a slope and it was a piece of cake to just add a self drain valve on the far end.