Hello All. My question is geared toward the Industrial, Commercial Buildings, but I'm sure one of our plumber members can shed some light on it for me. I live in California, and for about the past 10 years or so, all of the above mentioned buildings have to have a backflow preventor installed "above grade". To me it is a supid idea. I have seen cars run into them, they freeze in the winter, unless wrapped with insulation, and the ones that are wrapped look like crap. They would be very easy to tamper with, as far as stealing componets, or even sabatage. In my opinion, they should be in an under ground vault. Do any of you from California, or any other State know why they are put above ground, or give me the plumbing code so I can google it?