This redesigned bypass valve utilizes proprietary materials and a double rotary valve for more efficient water flow through water softener systems. The rubber and plastic materials complement each other’s tolerance capabilities with a balance between torque valve and sealing contact. It includes 1-sq-in. flow paths with low pressure drop and interchangeable rotor cartridge assemblies, ergonomic rotating handles, a non-corrosive reinforced thermoplastic one-piece body, and an outlet rotor to pressurize the system for improved valve startup.