BACKFLOW PREVENTION DEVICE

摘要

A backflow prevention device includes a main body holding a removable cartridge. The removable cartridge houses two independently acting check valves and, optionally, a relief valve. A first portion of the cartridge may be retracte d into a second portion of the cartridge, thereby reducing the overall length of the cartrid ge and facilitating the removal of the cartridge from the main body without the nee d to remove the backflow prevention device from a water supply system. The relief valve is contained in a removable cartridge. Each check valve may have a self cleanin g plunger bore comprising at least one spiral groove.