The Series 39 Tideflex InLine Check Valve from Red Valve provides backflow prevention and handles abrasive materials, sewage, sludge and other difficult slurries efficiently. The rubber check sleeve opens with as little as one inch of working pressure and seals drop-tight with backpressure, creating a unidirectional shutoff mechanism. The check valve is resistant to abrasion and rust and features totally passive operation. Red Valve