Answer: A backflow prevention device is a valve
assembly that is installed in the water piping that feeds the sprinkler
system. It prevents corrosive materials in the sprinkler piping from getting
out into the city water supply.
The assembly consists of two check valves sandwiched between to control
valves. The formal name for this valve is a “Double check valve assembly” or
“DCVA” for short. The DCVA is the most basic valve and is widely accepted by
the water departments. But some water departments may require a “Double
Detector Check Valve Assembly” or a DDCVA. This has a bypass meter on the
side of the assembly that records the quantity of water that passes through
If you have a DCVA or a DDCVA in your building for your fire sprinkler
system, check with your local authorities about required inspections on your
assembly. Many jurisdictions require it to be inspected every year.
Double Detector Check Valve