In plumbing terminology, what does the term "invert" refer to?

The term "invert" in plumbing terminology specifically refers to the lowest point of a channel in a pipe or conduit. This is significant because the invert level is crucial in determining the proper flow of water within the pipeline system. Knowing the invert level helps engineers and plumbers design efficient drainage systems by ensuring that gravity can effectively move wastewater through the piping.

Understanding the invert is essential for avoiding issues like blockages or improper drainage, which can lead to backups and other plumbing problems. For instance, if the invert is too high, it can create areas within the system where water may stagnate, leading to potential degradation of the pipes or unwanted odors.

Other options don't accurately describe the function or definition of "invert" in this context. The highest point of a pipe is more accurately referred to as the "crown," while the outer surface of a pipe pertains to its structural aspects rather than its channel. The connection point between two pipes is known as a "joint," which also does not relate to the concept of an invert.