Pipes in your system will have a C-Factor to help determine this loss. This is a measure of the roughness of the interior of the pipe that creates this friction. Different types of piping will have a different C-Factor, and the higher the C-Factor, the smoother the pipe.
A motif is a literary term that is an idea, object, or concept that repeats itself throughout a text. A motif gives clues to theme or reinforces ideas an author wants to emphasize. A motif generally reinforces the theme of the text. A motif must be repeated throughout a text to be considered a motif.
a constantly recurring symbol or motif in literature, painting, or mythology (this usage of the term draws from both comparative anthropology and from Jungian archetypal theory). In various seemingly unrelated cases in classic storytelling, media, etc., characters or ideas sharing similar traits recur.