Overflow questions

[ag6594]

I am beyond frustrated with trying to plumb my overflow to be silent. When Everything is turned off the water line almost covers the main drain elbow. But when it is on the water line goes much lower causing the incoming water form the internal side to splash down very loudly. The main drain is about as low as I can get it to the bottom. I've read countless hours of stuff over the past week but for whatever reason my brain just doesn't learn from looking at diagrams and this and that. This could be the most obvious solution or something very complicated but I am hoping that someone with more experience can tell me.

My drain pipe is about 1/2 inch below water line in sump.

 

[ag6594]

https://imgur.com/a/8LagHIx

Pic for reference

 

[Vinny Kreyling]

To avoid splashing you have to RAISE the pipes inside the box. They do NOT need glue so a simple coupling will allow you to adjust them to the right height.
The picture would be better straight into the box from the back side.

 

[Mcgeezer]

What I did when I built my drain pipe (PVC) was to put an adapter in my 1” bulkhead so that I could make the drain pipe a larger size at 1.25” - when a larger drain pushes water into a smaller pipe, it backs up the flow slightly and will help quiet everything. I made the top of the drain elbow just under the bottom of my overflow grates so that there is only a light sound of water coming into it.

I also drilled a 1/8” hole in the top cap to keep the pipe from creating a hard siphon, which quieted everything dramatically.

In the sump area, I have a 1” PVC drain coming from the bulkhead going into a ball valve which helps control the flow....and the drain exits into a filter sock. It took awhile to get it all figured out but I promise it works.