All check valves are designed to prevent pipeline backflow and prevent water contamination, equipment damage and flooding; there are different models that are designed for optimal performance in varying applications:
• Spring check valve - uses a spring-loaded disc that sits on a seat in the valve body and is held in place by a spring. Pressure from fluid flow in one direction pushes the disc away from the seat and allows fluid to pass. When the flow stops, the spring forces the disc back onto the seat.
• Swing check valve - uses a swinging disc that is pushed open by fluid flow in one direction. When the flow stops or reverses the weight of the disc swings it back into a closed position.
• Recoil check valve - Similar to a swing check valve, however the recoil valve has an inclined seat and body profile to reduce the damaging effects of water slam.
• Double hinge flap valve - simple valves featuring a flap attached with two hinges that allows flow in one direction and closes when flow stops or reverses.
• Ball break valve - a self-acting valve that uses a ball to prevent backflow. As the flow subsides the ball falls back into the valve seat, creating a seal and stopping any media from passing in the wrong direction.
• Twin plate check valve - two half-circle shaped plates are hinged and located inside the valve body, the plates swing open to allow flow in one direction, swinging shut if flow reverses.
