I searched for this but could not find the same situation. I have a cast iron 2" flange in the floor. I want to change over to PVC. I purchased a Fernco PlumbQwik P22U-205 coupler. As I understand you put the rubber insert into the flange then push the PVC pipe into it then hammer it down tight? I have tried to do this but can not seem to get the pipe tight. Anyone have any ideas to get this thing good and tight? Thanks for any help.