…Check Valve Prevents Backflow * Rated 125 PSI * Corrosion Resistant Engineered for maximum flow, quick response and positive shutoff. The PVC Sch 40 Slip x Slip swing check valves are designed for horizontal installations, but may be installed in up-flow only vertical installations. Check valves…

…Replace your existing worn or damaged windmill air stones in a matter of minutes. The replacement air stone includes a separate foot valve (backflow valve) that attaches to the top of the diffuser and prevents water from coming back into the airline. The air stone can also be used to add additional…

…selector valve allows you to adjust airflow between multiple air stones with one windmill. The backflow valve (or foot valve) works with the air stone to keep water from backing up in your airline, which could freeze in the winter months. Includes (1) Windmill Diffuser Air Stone, (1) Backflow Valve…

…flat on the bottom of your pond. Windmill Diffuser Air Stone with Backflow Valve and 2-Way Valve: Using an additional stone, you can aerate more effectively. Includes an additional air stone, backflow valve, and 2-way selector valve for equalizing airflow. Airline sold separately. Windmill Freeze…

…bottom of your pond. Windmill Diffuser Air Stone with Backflow Valve and 2-Way Valve: Using an additional stone, you can aerate more effectively. This windmill for sale includes an additional air stone, backflow valve, and 2-way selector valve for equalizing airflow. Airline sold separately.…

…your wooden windmill. Windmill Diffuser Air Stone with Backflow Valve and 2-Way Valve: Using an additional stone, you can aerate more effectively. This wooden windmill includes an additional air stone, backflow valve, and 2-way selector valve for equalizing airflow. Airline sold separately. Windmill…