The ultimate high-pressure Automatic Recirculation Valve. Type MRK, is used as a pump protection system for centrifugal pumps for water applications. The MRK valve protects centrifugal pumps from overheating and cavitation problems by automatically maintaining a minimum flow. At lower process flows, the check valve activates the bypass. When the system flow increases, the main check valve lifts off and modulates the bypass recirculation flow that returns to the system tank. When the check valve monitors enough flow, the bypass closes automatically. If the system detects a decrease in flow, the bypass is again restarted automatically.