plumber
Trade definition with interesting etymology about lead pipes
One who fixes or repairs pipes. Plumber has a "b" in it because pipes were originally made of lead, (lead seemed a logical choice at the time, because of its resiliancy against rust... then people discovered what lead poisening was, and rust no longer seemed so bad!) and lead's abbreviation on the periodic table is pb (derived from its latin name).
Plumbers are given little respect, but we wouldn't want to try to live without them.