4" PVC Full Port Backwater Valve

The Mainline Fullport Backwater Valve is the 'flagship' of the company. Established in 1997, this valve has revolutionized sewer protection across North America with its patented 'normally open' gate design. This valve is typically installed in homes or buildings that have basements, cellars, crawl spaces or area that are accessible for servicing. The normally open gate allows the sewer system to 'vent' any gases that may be causes by positive or negative pressures in the sewer line. The 4963 has a 'Clear View' top that makes inspection of the valve quick and simple for the building owner or plumber! As well, the 4963 comes with an integral clean-out for rodding the sewer lateral. Should rodding from the stack be necessary, the snake can easily pass over the open gate and be retracted with out doing any harm to the components.

• "Normally-open design" offers zero flow restriction
• "Normally-open design" allows free circulation of air through the Plumbing System
• "Clear Lid" easy visual inspection of unit
• "Built-in main-sewer cleanout" allows auguring of sewer