[1] Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications.
Plumbing originated during ancient civilizations, as they developed public baths and needed to provide potable water and wastewater removal for larger numbers of people.
[6] The Mesopotamians introduced the world to clay sewer pipes around 4000 BCE, with the earliest examples found in the Temple of Bel at Nippur and at Eshnunna,[7] used to remove wastewater from sites, and capture rainwater, in wells.
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 BC.
[15] Plumbing reached its early apex in ancient Rome, which saw the introduction of expansive systems of aqueducts, tile wastewater removal, and widespread use of lead pipes.
Improvement was very slow, with little effective progress made until the growth of modern densely populated cities in the 1800s.
During this period, public health authorities began pressing for better waste disposal systems to be installed, to prevent or control epidemics of disease.
Lead was the favoured material for water pipes for many centuries because its malleability made it practical to work into the desired shape.
About 100,000 feet of these wooden pipes were installed during WW2 in drainage culverts, storm sewers and conduits, under highways and at army camps, naval stations, airfields and ordnance plants.
Cast iron and ductile iron pipe was long a lower-cost alternative to copper before the advent of durable plastic materials but special non-conductive fittings must be used where transitions are to be made to other metallic pipes (except for terminal fittings) in order to avoid corrosion owing to electrochemical reactions between dissimilar metals (see galvanic cell).
1/2" PVC on the other hand is not the same size as 1/2" tubing, and therefore requires either a threaded male or female adapter to connect them.
Hollowed wooden logs wrapped in steel banding were used for plumbing pipes, particularly water mains.
Galvanized steel (often known simply as "galv" or "iron" in the plumbing trade) is relatively expensive, and difficult to work with due to weight and requirement of a pipe threader.
In the 1950s, plastics manufacturers in Western Europe and Japan began producing acrylonitrile butadiene styrene (ABS) pipe.
Present-day water-supply systems use a network of high-pressure pumps, and pipes in buildings are now made of copper,[34] brass, plastic (particularly cross-linked polyethylene called PEX, which is estimated to be used in 60% of single-family homes[35]), or other nontoxic material.
For example, plumbers use video cameras for inspections of hidden leaks or other problems; they also 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.
However, "opportunistic premises plumbing pathogens" have been recognized only more recently: Legionella pneumophila, discovered in 1976, Mycobacterium avium, and Pseudomonas aeruginosa are the most commonly tracked bacteria, which people with depressed immunity can inhale or ingest and may become infected with.
[44] Some of the locations where these opportunistic pathogens can grow include faucets, shower heads, water heaters and along pipe walls.
Reasons that favor their growth are "high surface-to-volume ratio, intermittent stagnation, low disinfectant residual, and warming cycles".
A high surface-to-volume ratio, i.e. a relatively large surface area allows the bacteria to form a biofilm, which protects them from disinfection.
[44] 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.
If permits are required for work, plumbing contractors typically secure them from the authorities on behalf of home or building owners.
[citation needed] In Australia, the national governing body for plumbing regulation is the Australian Building Codes Board.
However, several state level regulation acts are quite outdated, with some still operating on local policies introduced more than a decade ago.
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;[49] 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).
At the national level, the Environmental Protection Agency has set guidelines about what constitutes lead-free plumbing fittings and pipes, in order to comply with the Safe Drinking Water Act.
[53] Some widely used Standards in the United States are:[citation needed] In Canada, plumbing is a regulated trade requiring specific technical training and certification.
Standards and regulations for plumbing are overseen at the provincial and territorial level, each having its distinct governing body: [[Category:Bathrooms]