First, let me remind you that our sewer pipe is 10 inches back from the side of the RV. Second, we needed an extender. On measuring, it seemed that a 5 inch extension pipe and then the twist on dump valve would be ideal.
The first picture shows what we would expect to be our ideal configuration. Except that the valve hits the bottom of the RV. Also, the cap, after being detached from the original location fit great putting it on, but in taking it off, the valve came off too! The bottom photo is the current configuration. I have no faith in that. The problem seems the extension. I think when it gets warm again (barely above freezing here now - where are those 60 degree days when you really need it) we will attempt to remove the extender and just attach to the sewer pipe.
Hubby still doesn't think it will remain in place when we drive.