Clear PVC slip and compression swing check valves preventing backflow in waste water lines, sump pump disposal lines, sewage lift stations or ejector systems. The open position allows for unobstructed continuous flow with minimal head loss, make these check valves a favorable choice for sump pump disposal lines, sewage lift stations, and waste water lines to prevent backflow. Swing check valves are designed for horizontal installation, but can be installed vertically with flow going upward. All check valves must be installed with the flow-arrow pointing in the direction of the flow of the system. Swing check valves must NOT be installed upside-down. The flow velocity should not exceed 5 ft./second.For water use only. DO NOT USE FOR COMPRESSED AIR OR GASES. Recommended for sump & sewage applications NOT for well water applications.