VistaCheck™ Dual Check Valve Backflow Preventer (1/4") VistaCheck™ Dual Check Valve Backflow Preventer (1/4") CVVC250-A VistaCheck™ is a QAI-certified dual check valve backflow prevention device that can eliminate the need for expensive reduced pressure zone (RPZ) valves, vacuum breakers, and air gaps. Where to Buy x Category - Any - Dealer Partners Sales Representative Strategic Markets Schools Representative Accutron™ Equipment Sales Zip Code Find Representative Reset No results found. Please try a different search or explore: Sales Representatives | Dealer Partners | Strategic Markets | Schools | Accutron