Hi Everybody-
A year or two back I posted about how when my sump pump would shut off I would hear a very noticeable CLUNK. I thought it was related to the check valve I had. Turns out I was right. I had tried a Flo-tec and then a Zoeller check valve. Both were the same basic design and were 'clunkers'. Recently I just got a Campbell #B-0823-15C spring loaded check valve ($23 shipped from Acehardwareoutlet). It's great and now there is no 'clunk' whatsoever when the sump pump shuts down. Just wanted to give some feedback to the group in case anybody else is looking for a quiet check valve that works.
Another neat thing about it is that the body is clear so you can see inside the checkvalve.
Kevin