Mainline Fullport Backwater Valves offer the right solution for your sewer backup problems. SPECIAL OFFER: Mainline Backwater Valve "Combo" with Access Box ($89.00 value if purchased separately) Valves without Access Box are also available with a slight shipping discount in the price.
Protect Your Home with a Backwater Valve
Orders must be placed online by Credit Card,
copyright 2004-2017 Backwater-Valves.com.
backwater-valves.com is independently owned and resells products produced and manufactured by Mainline of Canada and assumes no liability for the installation of backwater valves and related products.
Be sure to check with the plumbing authority in the municipality in which your valve is to be installed to insure that your installation is in compliance with local code, and be sure have your valve inspected by your local plumbing inspector after installation. Inspect your valve frequently; the Backwater Valve through its clear plastic housing top, and the Adapt-A-Valve, by removing the gate cassette.
Pipe end-to-end, the Adapt-A-Valve takes up 6" of run in your line and the outlet is 1-1/2" LOWER than the inlet, so in just 6" the level of the pipe at the outlet side needs to be 1-1/2" lower.
Pipe end-to-end, the Backwater Valve takes up 12" of run in your line and the outlet is 3/4" LOWER than the inlet, so in just 12" the level of the pipe at the outlet side needs to be 3/4" lower.
Depending upon the amount of slope in your line (2% minimum is required for proper operation), you may need to replace several feet of pipe downstream from the valve to average out this "loss" of fall.
NOTE: New Straight-Fit and ML-FR4 require less slope. (refer to detail pages for these products)
Mainline Valve Warranty
Backwater-valves.com accepts these