Valve definition
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
Work at the plant hydraulic
Every plumber has a practical education in the field of hydraulics supported by practices in one of the plumbing. Only a certificate of holding of such practices would constitute a hydraulic plant manager ensures that the worker employed by him will be competent and honest. Announcements of job opportunities in the hydraulic plant are posted on various bulletin boards and websites dedicated to people looking for work. It also happens that to find a job at the plant hydraulic will be visiting his website. Through reading this page you will be instantly familiar with the character of the work performed by the hydraulic plant looking for new employees.
Snakes for plumbing
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