Plumbing performed during house construction
Large companies engaged in hydraulic performance of full-service plumbing. They can be rented during the construction of the house. They also participate in the process of putting up apartment buildings and schools of all sizes. It seems that the least complicated plumbing services are performed in the course of construction of the house, because they are limited to the performance of domestic water supply and sewage, and in the case of apartment blocks need to make a detailed plan of such a network adequate to the number and position of the individual apartments. However, in the case of schools you need to equip the bathroom in the right amount of sinks, where you will be able to wash their hands after using the toilet. In schools, sports can also stand up showers.
About plumbing - Wikipedia
Plumbing is any system that conveys fluids for a wide range of applications. Heating and cooling, waste removal, and potable water delivery are among the most common uses for plumbing however plumbing's not limited to these applications.1 Plumbing utilizes pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids.2 Trades that work with plumbing such as boilermakers, plumbers, and pipefitters are referred to the plumbing trade. In the Developed world plumbing infrastructure is critical for public health and sanitation.
Wikipedia about Valves
A valve is a device that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure. The word is derived from the Latin valva, the moving part of a door, in turn from volvere, to turn, roll.
The simplest, and very ancient, valve is simply a freely hinged flap which drops to obstruct fluid (gas or liquid) flow in one direction, but is pushed open by flow in the opposite direction. This is called a check valve, as it prevents or "checks" the flow in one direction. Modern control valves may regulate pressure or flow downstream and operate on sophisticated automation systems.