Internal Backwater Valve,3-F 3" Float Model Flood-Guard for 3-inch Flood Drains,Drain Backflow Preventer for Sewer Flood Protection

Replaced the old one an it works great.

This is excellent. I replaced one that I had for years but corroded. The key to using these is to put it down into the PVC tube just far enough that the center "pin" sticking up is about 1/4 inch below the level of the floor. This is made well, is a quality item, and is easy to install. I may buy another one so that in 20 years when this one is all nasty, I can replace it easily.

I PURCHASED THESE FOR MY BASEMENT FLOOR DRAINS. BOTH DRAINS HAVE CONDENSATION LINES THAT DISCHARGE INTO THEM. THE FAULT I FOUND WAS THE SPRING WAS TOO TIGHT AND THE RUBBER STOPPER WOULD NOT ALLOW ANY WATER TO GO "DOWN". I HAD TO CUT A FEW COILS OFF THE SPRING TO ALLOW THE RUBBER STOPPER TO "HANG" SLIGHTLY DOWN. NOW THE CONDENSATION WILL GO DOWN.WE FINALLY HAD A BIG ENOUGH RAIN WITH LAST YEAR'S HURRICANE AND THEY WER PUT TO THE TEST. IT WASN'T A TOTAL SUCCESS, BUT DEFFENITELY BETTER THAN NO BACKFLOW DEVICE. A SMALL AMOUNT OF WATER SEEPED UP THROUGH THE FLOOR DRAINS, BUT DEFINATELY KEPT THE BASEMENT FROM FLOODING COMPLETELY. PROBABLY WOULD HAVE BEEN 100% IF I DIDN'T HAVE TO MAKE A MODIFICATION TO THEM.

This device has saved my basement twice from being flooded with several inches of water. On two occasions in the past year, we received heavy rainfall (4+ inches). While several neighbors had their basements flooded with inches of water, I only experienced a small trickle due to dirt/debris on the rubber plunger.A couple of recommendations:Get a tube of silicone grease and apply it once or twice a year to the rubber seal to keep it from drying out. If it dries out, it may not form a good seal when floodwater comes up.I also highly recommend a water leak sensor that sets off an alarm if water starts to rise and bypasses the valve.

It does require you to cut the spring down if you want water to drain. The spring it comes with is pretty strong, and would require several inches of water to drain through it. I cut it down so that it barely seals.I bought a house where the basement had flooded from a back up of the city lines. I installed this in the basement floor drain after it happened to me and hoped for the best. I wasn't sure if it worked, but a year later I ended up having another back up, except it came up through my basement shower drain (being the next lowest point). The good news is that all the black stuff stayed in the shower pan. I'm buying a 2nd one for the shower now, and I'd like to think the toilet won't be the next place to back up. If a couple years go by and there's not another back up, I'd love to refinish the basement.

I noticed a warning that this item has a very high return rate only after I purchased it and now I know why. The spring is way too tight. You can prob put a gallon of water on top and it still won't open. Someone had a review on how you can fix this by cutting part of the spring, but shouldn't it just work? Someone also mentioned that you're supposed to remove the spring, but kinda defeats the purpose of keeping out the sewer odor since the plunger would always be open.Nice idea, but you gotta fix the product and it seems so simple.

It did not fit perfectly in a 4-in cast iron sewer trap. It might fit perfectly in a 4"PVC trap.

A+. I deal with basement back ups when the city streets flood. Sump pump is fine, storm sewer is issue a backflow valve in the yard would cost thousands to install. This worked great so far in my basement. Last time I would’ve had an issue it barely let any water seal past the gasket edges. Usually I’d have 2-4” in the basement under these circumstances. I can probably tighten it a little more again, but it was very tight to begin with. Hold it with 1 hand and start screwing the 4 screws in a circle. Once snug you can crank it tight. Lean edges as best as possible. Mine was cast iron so hard to clean. Fit well. Works well. Also best one I’ve seen to allow water to go in, and not clog it up.