Back Flow Device

I am going through the process of applying for my IQP (Independent Qualified Person Back Flow Testing). In my duties involved in my work I will be working with a lot more of these and other Back Flow Devices testing them. This one in this set up on the Right hand side is an RPZD ( Reduced Pressure Zone Device ). The whole idea of these is to prevent contamination of water Back Flowing from a property into the water reticulation system. The paper work involved with a compliance takes the most amount of time.