1 In the U.S., infection with hepatitis C is the most common cause of chronic hepatitis and the most common reason for liver transplantation.
This is a common problem with ABY boxes that do not have isolation. You need an ABY box that has transformer isolation built in like the Radial BigShot ABY, Bones Twin City or Tonebone Switchbone, which is probably the best ABY box ever made.
The double check backflow preventer is the only true backflow preventer which does not have a vent to allow air to enter the lines or to allow water to escape when backflow occurs. It relies entirely on the tight seal of the two check valves to prevent backflow.