The Mainline Fullport Backwater Valve's "normally open" design allows unrestricted sewage flow. Because of its Fullport design, it requires minimal homeowner maintenance when installed properly, and provides the best in backflow protection.
Installation of Backwater Valve
Retrofit Installation Of Backwater Valve
Testing the Unit
Mainline Fullport Backwater Valve Specifications
Access Box Specifications
How to Choose Which Valve I Need?
Why a Mainline Valve
How it Works
Mainline Backflow Products
Canadian Home Builders' Association
Mechanical Contractors Association of Alberta