slamming check valve on basement ejection pump

crankcase

I have a check valve mounted about 18" above floor level for my ejection pump. Any time we do laundry or the water softner cycles we hear the slamming of the check valve every 5-8 minutes after the pump stops.

How can I quiet or eliminate the loud slam of the check valve? Maybe another check valve closer to the ceiling?

Billy_Bob

Is it all metal pipe? Through which the sound would resonate?

If yes, how about isolating the check valve from the metal pipe with rubber or plastic connections?

crankcase

No metal it's 2" ABS.

Billy_Bob

And a 2" check valve? Good grief!

Do you need that large?

It is of course the weight of all that water falling back down on the check valve. And that would be reduced with the valve higher up as you suggested. (Less water weight.)

And/or a smaller line and be no smaller than the pump output of course. But with a smaller line, then less water weight...

crankcase

Pretty sure the pump has 2" outlet. We just had the house built this is our second winter. I was thinking an additional check halfway up the run. Just wasn't sure if there were any other solutions.