2in Visible Check Valve Non Return Anti Backflow Accessories for Swimming Pool One Way Pipe Item Type: Check Valve Material: ABS+PVC Weight: Approx. 727g/25.6oz Nominal Diameter of Interface: Approx. 2in/60.2mm Purpose: Install at the outlet of the water pump to prevent water from flowing back and damaging the pump impeller Features: High-quality material, transparent and visible, anti-corrosion and durable, simple installation Installation and use instructions: 1. Determine whether the diameter of the pipe to be installed is consistent with the installation diameter of the valve. The nominal diameter of the valve is: 2 inches 2. Before the valve is used, a manual operation test should be performed to observe whether the sealing baffle of the valve will rebound to the original position to determine whether the valve is damaged during transportation 3. Before installing the valve, check: A. Whether the water pump on the pipeline used is in the closed state: B. Whether there is debris in the valve cavity, and keep the inner cavity of the door clean: C. The flow direction marked on the valve must be consistent with the flow direction of the pipeline liquid. 4. Before installation, clean the oil stains or other debris on the installation nozzle and inside the valve installation port.