I agree with BigInch, it is probably a translation issue.
Maybe, if the pipe is buried, it is describing a valve located where the pipe "breaks" through the ground surface in order to go up and over the water. Thus maybe a literal, but poor, description in colloquial language caused the confusion.
I worked an college internship at a DuPont chemical plant which was quite old and had generations of locals who had made up the workforce over time. Their terminology confused me some, but other student engineers, who weren't fluent in hillbilly-ese, weren't able to make any sense of it. There was one guy from Indonesia, that poor guy was completely lost.
Maybe that language is properly called hillbillian.