Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids.Plumber Job Description On a job, plumbers work with pipe systems by installing them, making necessary repairs and doing preventative maintenance to keep them running smoothly. The systems that they work on can be found in a variety of settings, such as industries, schools , private homes and public buildings.