Watertight door non-return flood defence valve designed to discourage rats and rodents from entering a property via the drainage system. Positioned securely into a manhole chamber, the valve works by preventing a back flow of waste water into a property by effectively sealing the chamber outlet in a flood situation. Manufactured from stainless steel. Suitable for use in clay, PVC and cast iron pipe systems to suit installation within either an outlet or inlet of a drainage chamber. Untreated Plastic & Stainless Steel Construction For use Against Rodents Suitable Pipe Diameter: 150mm Suitable for Plastic, Clay, Concrete & Cast Iron Pipes Suitable for Domestic Use Single Flap Watertight Untreated Plastic & Stainless Steel Construction For use Against Rodents Suitable Pipe Diameter: 150mm Suitable for Plastic, Clay, Concrete & Cast Iron Pipes Suitable for Domestic Use Single Flap Watertight