BB_TX wrote:
I have that same type fitting and is all I have ever used as it gives a good seal in most all sewer pipes. They do not want someone just hanging a loose sewer hose done the dump pipe with no seal.
This is probably true at commercial CG's, but most Fed parks we've been to just have a straight pipe hole at the dump station, I have just what the OP has & never been questioned, even when they said a doughnut was required.
At a private CG in NY, rules stated a doughnut was required, I told the owner that I didn't have one, when I showed him what I had, (exactly what OP has) he said that was fine.