High Hazard applications like this should have the RP inspected by a Licensed Back Flow Prevention Assembly Tester annually. This is the only way to understand if the device is working. Looking at the device installation is not an indication of proper working of the device. Many brand new units can fail due to turning on the water too fast and dislodging a spring or seal. Trash or glue or pipe shavings can also cause a unit to fail upon installation. I would also recommend that you watch the test because it can be interesting to watch.
Dan
It also prevents the (PAPER PUSH) from less morally responsible testers