Plumbing is the system of pipes, drains, fittings, valves, and fixtures installed for the distribution of potable water for drinking, heating and washing, and waterborne waste removal. “Plumbing” also refers to the skilled trade which deals with installation and maintenance.
The plumbing industry is a basic and substantial part of every developed economy. The word derives from the Latin plumbum for lead, as the first effective pipes used in Roman era were lead pipes.
Plumbing equipment includes devices often hidden behind walls or in utility spaces which are not seen by the general public. It includes water meters, pumps, expansion tanks, backflow arrestors, water filters, UV sterilization lights, water softeners, water heaters, heat exchangers, gauges, and control systems.
Specialized plumbing tools include pipe wrenches, flaring pliers,pipe vice,pipe bending machine,pipe cutter, dies and joining tools such as soldering torches and crimp tools. New tools have been developed to help plumbers fix problems more efficiently. For example, plumbers use video cameras for inspections of hidden leaks or problems, they use hydro jets, and high pressure hydraulic pumps connected to steel cables for trench-less sewer line replacement.
Flooding from excessive rain or clogged sewers may require specialized equipment, such as a heavy duty pumper truck designed to vacuum raw sewage.
Most large cities today pipe solid wastes to sewage treatment plants in order to separate and partially purify the water, before emptying into streams or other bodies of water. For potable water use, galvanized iron piping was commonplace in the United States from the late 1800s until around 1960. After that period, copper piping took over, first soft copper with flared fittings, then with rigid copper tubing utilizing soldered fittings.
The use of lead for potable water declined sharply after World War II because of increased awareness of the dangers of lead poisoning. At this time, copper piping was introduced as a better and safer alternative to lead pipes.