Plumbing

A complex arrangement of rigid steel piping, stop valves regulate flow to various parts of the building

Water and sewage pipes of a Jerusalem building built around 1930

Plumbing is the system of pipes and drains installed in a building for the distribution of potable drinking water and the removal of waterborne wastes, and the skilled trade of working with pipes, tubing and plumbing fixtures in such systems. A plumber is someone who installs or repairs piping systems, plumbing fixtures and equipment such as water heaters. The plumbing industry is a basic and substantial part of every developed economy due to the need for clean water, and proper collection and transport of wastes. The word "plumbing" comes from the Latin plumbum for lead, as pipes were once made from lead.

Plumbing is usually distinguished from water and sewage systems, in that a plumbing system serves one building, while water and sewage systems serve a group of buildings or a city. Plumbing fixtures are exchangeable devices that can be connected to a building's plumbing system.

Plumbing was extremely rare until the growth of modern cities in the 19th centuries. At about the same time public health authorities began pressing for better waste disposal systems to be installed. Earlier, the waste disposal system merely consisted of collecting waste and dumping it on ground or into a river.

History

See also: Sanitation in ancient Rome and History of plumbing

Roman lead pipe with a folded seam, at the Roman Baths in Bath, England

Plumbing originated during the ancient civilizations such as the Greek, Roman, Persian, Indian, and Chinese civilizations as they developed public baths and needed to provide potable water, and drainage of wastes. Standardized earthen plumbing pipes with broad flanges making use of asphalt for preventing leakages appeared in the urban settlements of the Indus Valley Civilization by 2700 B.C. The Romans used lead pipe inscriptions to prevent water theft.

Improvement in plumbing systems was very slow, with virtually no progress made from the time of the Roman system of aqueducts and lead pipes until the growth of modern cities. Until then waste disposal systems merely consisted of collecting waste and dumping it on ground or into a river. In the 19th century, public health authorities began pressing for better waste disposal systems to be installed. Eventually the development of separate, underground water and sewage systems eliminated open sewage ditches and cesspools.

Most large cities today pipe solid wastes to treatment plants in order to separate and partly 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 took over, first with 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 the dangers of lead poisoning. At this time, copper piping was introduced as a better and safer alternative to lead pipes.

Materials

Water systems of ancient times relied on gravity for the supply of water, using pipes or channels usually made of clay, lead, bamboo wood or stone. Hollowed wooden logs wrapped in steel banding were also used for plumbing pipes, particularly water mains. Logs were used for water distribution in England close to 500 years ago. US cities began using hollowed logs in the late 18th through the 19th centuries.

Present-day water-supply systems use a network of high-pressure pumps, and pipes are now made of copper, brass, plastic, or other nontoxic material. Due to lead's toxicity, lead has not been used in modern water-supply piping since the 1930s in the United States, although lead was used as a solder until 1986. Drain and vent lines are made of plastic, steel, cast-iron, and lead.

The "straight" sections of plumbing systems are pipes or tubes. A pipe is typically formed via casting or welding, where a tube is made through extrusion. Pipe normally has thicker walls and may be threaded or welded, where tubing is thinner-walled and requires special joining techniques such as brazing, compression fitting, crimping, or for plastics, solvent welding.

Components

Piping being placed for a sink

In addition to the straight pipe or tubing, many fittings are required in plumbing systems, such as valves, elbows, tees, and unions. The piping and plumbing fittings and valves articles discuss these features further.

Plumbing fixtures are designed for the end-users. Some examples of fixtures include water closets (also known as toilets), urinals, bidets, showers, bathtubs, utility and kitchen sinks, drinking fountains, ice makers, humidifiers, air washers, fountains, and eye wash stations.

Equipment

A plumber wrench for working on pipes and fittings

Plumbing equipment, not present in all systems, include, for example, water meters, pumps, expansion tanks, backflow preventers, filters, UV lights, water softeners, water heaters, wrenches, heat exchangers, flaring pliers, gauges, and control systems.

Now there is more equipment that is technologically advanced and helps plumbers fix problems without the usual hassles. 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.

Systems

Copper piping system in a building with intumescent firestop being installed by an insulator, Vancouver, Canada

The major categories of plumbing systems or subsystems are:

• Potable cold and hot tap water supply
• Plumbing drainage venting
• Septic systems
• Rainwater, surface, and subsurface water drainage
• Fuel gas piping

For their environmental benefit and sizable energy savings hot water heat recycling units are growing in use throughout the residential building sectors. Further ecological concern has seen increasing interest in grey-water recovery and treatment systems.

The New York City steam system is an example of a large district heating system.

Plumbing may also include hydronics, which involves heating and cooling systems utilizing water.

Firestopping

Self-levelling silicone firestop installation in mechanical service penetration in 2 hour rated concrete floor

Firestopping is required where mechanical penetrants traverse fire-resistance rated wall and floor assemblies, or membranes thereof. This work is usually done worldwide by the insulation trade and/or specialty firestop sub-contractors.

Regulation

Much of the plumbing work in populated areas is regulated by government or quasi-government agencies due to the direct impact on the public's health, safety, and welfare. Plumbing installation and repair work on residences and other buildings generally must be done according to plumbing and building codes to protect the inhabitants of the buildings and to ensure safe, quality construction to future buyers. If permits are required for work, plumbing contractors typically secure them from the authorities on behalf of home or building owners. In the United Kingdom the professional body is the Chartered Institute of Plumbing and Heating Engineering (educational charity status) and it is true that the trade still remains virtually ungoverned; there are no systems in place to monitor or control the activities of unqualified plumbers or those home owners who choose to undertake installation and maintenance works themselves, despite the health and safety issues which arise from such works when they are undertaken incorrectly; see Health Aspects of Plumbing (HAP) published jointly by the World Health Organization (WHO) and the World Plumbing Council (WPC). WPC has subsequently appointed a representative to the World Health Organization to take forward various projects related to Health Aspects of Plumbing.

See also

• Active fire protection
• Coupling (piping)
• Double-walled pipe
• Elbow (piping)
• Heat pipe
• Nipple (plumbing)
• Passive fire protection
• Pipe cap
• Pipe fitting
• Piping
• Piping and plumbing fittings
• Plastic pipework
• Plumbing & Drainage Institute
• Street elbow
• Trap (plumbing)
• Trap primer
• Union (plumbing)
• Valve
• Victaulic
• Water pipe

Further reading

• Teresi, Dick; et al. (2002). Lost Discoveries: The Ancient Roots of Modern Science--from the Babylonians to the Maya. New York: Simon & Schuster. pp. 351–352. ISBN 0-684-83718-8. 

External links

• The Wiktionary entry for plumbing
• Quotations related to Plumbing at Wikiquote
• Plumbing at Wikibooks
• ATSDR Case Studies in Environmental Medicine: Lead Toxicity U.S. Department of Health and Human Services