15-23-5 Backflow Prevention Methods; List.
All backflow prevention assemblies shall be installed, maintained and tested in accordance with the parameters of the manufacturer and the Utility. The following are the approved types of backflow prevention assemblies which the department may require. (See Appendix A, on file in the office of the Town Clerk, for schematics and additional information.)
A. Air Gap (AG): The unobstructed vertical distance through free atmosphere between the lowest point of a water supply outlet, pipe or faucet supplying potable water to a tank, plumbing fixture or other device and the flood level rim of the tank, plumbing fixture or other device. An approved air gap shall be at least twice the diameter of the supply pipe or faucet and in no case less than one (1) inch.
B. Reduced Pressure Principle Assembly (RPA): A backflow prevention assembly containing two (2) independently acting, approved check valves together with a hydraulically operating, mechanically independent pressure differential relief valve located between the check valves, and at the same time below the first check valve. The assembly shall include properly located test cocks and tightly closing shutoff valves at each end of the assembly.
C. Reduced Pressure Principle Detector Assembly (RPDA): An assembly composed of a line size approved reduced pressure principle assembly with a bypass containing a specific water meter and an approved reduced pressure principle assembly.
D. Double Check Valve Assembly (DC): A backflow prevention assembly composed of two (2) independently acting, approved check valves, including tightly closing shutoff valves located at each end of the assembly and fitted with properly located test cocks.
E. Double Check Detector Assembly (DCDA or DDCVA): An assembly composed of a line size approved double check valve assembly with a bypass containing a specific water meter and an approved double check valve assembly.
F. Pressure Vacuum Breaker Assembly (PVB): A backflow prevention assembly containing an independently operating, loaded check valve and an independently operating, loaded air inlet valve located on the discharge side of the check valve. The assembly shall be equipped with properly located test cocks and tightly closing shutoff valves located at each end of the assembly.
G. Spill-Resistant Pressure Vacuum Breaker (SVB): An assembly containing an independently operating internally loaded check valve and independently operating loaded air inlet valve located on the discharge side of the check valve. The assembly shall be equipped with a properly located test cock, properly located bleed/vent valve and tightly closing resilient seated shutoff valves located at each end of the assembly.
Any backflow prevention assembly equipped with test cocks shall have been issued a certificate of approval by the USC Foundation for Cross-Connection Control and Hydraulic Research. Any backflow prevention assembly not equipped with test cocks shall be certified by a third party entity unrelated to the product’s manufacturer or vendor and approved by the ADEQ. ((O)07-21, 03/21/2007; (O)98-03, 01/07/1998. Formerly 15-23-4)