Review on 🔧 White 4-Inch Oatey 43904 PVC Backwater Valve for Improved SEO by Sheppard Priest

I couldn't find this 4 inch item anywhere other than in PVC where the rest of the ABS sewer system is but no problem: use an all purpose cement. The existing line pipe necessitated the use of about 30 cm of ABS pipe to allow a 4 inch rubber grommet to connect the line upstream. It doesn't require a lot of pressure (hopefully) so it shouldn't be a problem. The block also serves as a sweep. The top cover of the inspection screw is located inside the 5" (or 6"?) OD flange so you can pull the "inspection tube" back to the surface when buried. I think in our area the pipes should be at least 18 inches below the surface to the top of the pipe? Proper diameter 18 inch pipe and a protective coating are therefore required. The non-return valve is simply removed from below, held in place by a screw in the inspection cover, with no risk of it falling out anywhere. There is a rubber seal, I hope synthetic.