Canplas 73009 Backwater Valve with 4-Inch PVC, White

This Canplas valve has worked excellently for me. While it’s true that it needs occasional cleaning, it’s a small price to pay to prevent a disaster inside my home. I recommend it to anyone who needs one for their own house—you won’t regret it.

Work great the drainage. Good size

You can't find these at your typical home depot store/Lowe's . Great quality,easy installation and great performance.

Exactly what was needed, understand though, the connection may not link with your existing pipe. I have a no pressure drainage pipe and this is a schedule 40 connection, but the easy fix is a rubber adapter(found at home depot 4" sch 40 to drain pipe w/pipe clamps already installed)

I fell happily item works so good recommended

Living in a high Radon area, my initial tests were 15.4. I had a radon mitigation fan installed that took it down to 7.2. I really had no idea how to fix this until i did some research and found out that there was not enough negative air pressure under my slab to properly fix this issue. After installing this at the outside drain, my radon has been at 1.35 for a month. I bought a radon tester years ago that gives me short and long-term readings. I leave it on all of the time. I am convinced that I have solved my issue. I even sent a test out from my radon installer that came back at 1.2.

Easy installation,fit and quality

I had originally bought this for a 2nd building that is lower than my home. Sewage would back up into my shop any time the sewer system backed up.In the end, I realized that what was needed was a sump pump and while installing that. I installed the backflow on the downside of sump tank and routed the sump pump ejection side downstream from the backflow valve. So Now should my sump pump fail I wll still have flow out from the sump tank slow as it was before but not a total blockage that I would have had