Yes start at the back of the pipe and work your way to the head.
I know they will be off and on a work bench but thats the idea.
So they dont scoop water and road filth.

I have no faith in human perfectability. I think that human exertion will have no appreciable effect upon humanity. Man is now only more active - not more happy - nor more wise, than he was 6000 years ago. Edgar Allan Poe