plumbers Barnet Pipes made of steel - Wikipedia
Galvanized steel potable water supply and distribution pipes are commonly found with nominal pipe sizes from 3?8 inch (9.5 mm) to 2 inches (51 mm). It is rarely used today for new construction residential plumbing. Steel pipe has National Pipe Thread (NPT) standard tapered male threads, which connect with female tapered threads on elbows, tees, couplers, valves, and other fittings. 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. It remains in common use for repair of existing "galv" systems and to satisfy building code non-combustibility requirements typically found in hotels, apartment buildings and other commercial applications. It is also extremely durable and resistant to mechanical abuse. Black lacquered steel pipe is the most widely used pipe material for fire sprinklers and natural gas.
Źródło: https://en.wikipedia.org/wiki/Plumbing
City of hydraulic
City of hydraulic engaged in the execution of various works. Some of them are contracted by the city authorities and owners of various public buildings, and others by owners of private flats and houses. Therefore, the scope of hydraulic works performed in cities is very wide. It includes both Pip drains and supervising the work performed after the flooding of the city by heavy rains and repair of hydraulic failure in flats and houses and installation of new sanitary facilities. Such an installation can be performed by plumbers working alone or working in the company hydraulic system. While the work is carried out after heavy rains need to rent a large company hydraulic system.
Wikipedia facts
Water supply and sanitation has been a primary logistical challenge since the dawn of civilization. Where water resources or infrastructure or sanitation systems are insufficient for the population, people fall prey to disease, dehydration, and in extreme cases, death.
Major human settlements could initially develop only where fresh surface water was plentiful, such as near major rivers. Over the millennia, technology has dramatically increased the distances across which water can be relocated, but the availability of clean and fresh water remains a limiting factor on the size and density of population centers, and is expected to remain so into the foreseeable future.
Źródło: https://en.wikipedia.org/wiki/History_of_water_supply_and_sanitation