bukhrn wrote:
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.
Same experience here... out in the southwest. Out here those straight pipe holes usually have a heavy iron lid hinged cover that, if possible, I will place on top of or against the elbow to keep it secure. Often there is a rock there as well which can be placed on or up against that iron lid. Never have had an issue.
Mike