Help with overflowing sump system

[Peter Peng]

Originally Posted by RDNanoGuy

You could also put a flap checkvalve right on the output of the pump. The weight of the water in the return line will shut the valve when the water stops preventing the back siphon. I know alot of people don't use them but I put them in all my systems and have yet to have one fail. Combine that with a siphon break hole up top and you should be pretty safe all round.

Did a quick search and I think a flap checkvalve looks very efficient. Do you know where I could get one specific to my size of tubing? I will measure the diameter tomorrow. Also I dont have lots of supplies for plumbing so what needed pieces do I have to purchase before installing the valve? also where would I drill the hole and how big would it be?

Many thanks to the helpful replies