Backflow Testing at a Dentist Office
As I tested the first device of three devices, I saw the first one fail. I saw the needle on my Watts TK-99E fall to about 4 pounds on the apparent reading across the number one check valve.
I continued to test and had to take apart the number 1 check. Here is what I found.
I was able to clean the device and put it back in service from a Fail to a Pass.