Back flow device testing

Proper Backflow devices are required to prevent hazardous and potentially hazardous water from returning to water supply. These device have check valves and a discharge vent to break the siphon in plumbing should a reverse or back flow happen. A fire truck hooks up to hydrants they can pull water from homes plumbing and irrigation should there be no device. A construction mishap that breaks a major water main supply can also cause this condition. Double check devices are sealed and have no vent to atmosphere port. Should both checks be lodged with debris  its useless and will reverse flow. The Correct device Reduce Pressure Zone (RPZ) assembly vents and breaks siphon to atmosphere and eliminates backflow of nasty sitting water irrigation pipes can develop. Like a straw and your finger it breaks the siphon hold water can have to reverse flow. Happy Heads use of check valve  sprinkler heads traps water from getting in and out of the pipes at the head and the first link in the chain of safe water compliance. Ensuring these devices are doing as expected is prudent and required. Hence the routine test.