plumbing Hammersmith Encyclopedical explanation of the 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.
Źródło: https://en.wikipedia.org/wiki/Valve
Plumbing performed in various sizes towns
Hydraulic works carried out in the towns of different sizes have different scope. They can be carried out on behalf of local authorities, if any part of the village needs to be connected to the municipal sewer system or the village was flooded by torrential rains. At the same time the hydraulic assistance can apply the owners of private houses, in which there have been some failures. Depending on the type of failure, they can order the execution of hydraulic works in normal mode, or call the emergency hydraulic. Such hydraulic ambulance is able to reach a flooded home, even during the weekend. While minor work will be done by appointment convenient for the homeowner term.
Plumbing snakes - some types
Hand auger / hand spinner
Hand augers are useful for clearing sink and bathtub drains. They are unsuitable for sending through flush toilets, because the wire might damage the bowl; also, flush toilets have relatively large drain pipes in which the narrow snake can be become tangled. (A 1?4-inch cable, for example, should never be used in a drain with a calibre of more than two inches.)
Closet auger / toilet auger
The closet auger (named after water closet) feeds a relatively short auger through a hook-shaped length of metal tubing. The hook shape makes it easier to feed the auger into the toilet. A plastic boot on the end of the auger protects the finish of the visible porcelain. Since most toilet clogs occur in the trap built into the bowl, the short cable is sufficient to break up or retrieve the greater majority of clogs.
Źródło: https://en.wikipedia.org/wiki/Plumber%27s_snake