boiler service Harrow 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
Plastic pipework
Plastic pipework is used for the conveyance of drinking water, waste water, chemicals, heating fluid and cooling fluids, foodstuffs, ultra-pure liquids, slurries, gases, compressed air and vacuum system applications.
Plastic pipe systems fulfil a wide variety of service requirements. Product standards for plastics pipe systems are prepared within the standards committee known as CEN/TC155. These requirements are precisely described in a complete set of European Product Standards for each application alongside their specific characteristics.
For example:
Conveyance of drinking water: Hygienic requirements
Conveyance of gas: Highest Safety requirements
Plastic pipes for radiant heating and floor heating: Temperature resistance over decades
Sewer applications: High chemical resistance.
Plastic pipes are perfectly capable of fulfilling the specific requirement for each application. They do so with a high level of performance over a long lifetime and with reliability and safety.
The key factor for success is achieved by maintaining consistently high quality levels. For plastic pipe products, these levels are closely defined by the different standards.
Źródło: https://en.wikipedia.org/wiki/Plastic_pipework
Plumbing - from 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.
Źródło: https://en.wikipedia.org/wiki/Plumbing