Valves
Valves are mechanical devices that control the flow of fluids such as gas, liquid, fluidised solids, slurries, and so on, by opening, closing or partially obstructing a passage.
Some common household examples of valves include:
- A tap that when turned opens a valve to release pressurised water.
- A toilet that when flushed opens two valves – one that allows water to escape, and another that refills the toilet with more water.
- A gas cooker hob that opens a valve to allow more gas to increase the flame size.
Simple valves are typically made up of several parts; a solid metal outer casing, a rubber or plastic inner seal, and a body which opens and closes, fitting into a seat.
An automated or manual mechanism is used to open and close valves. For high-pressure flow pipework, opening and closing manually can be physically difficult, often requiring a long lever or large wheel. Big valves can be operated using hydraulic rams.
There are several different types of valves, including:
- Ball: A hollowed-out ball sits inside a pipe obstructing the flow and swivelling through 90-degrees when turned.
- Butterfly: A disc sits inside a pipe and swivels sideways or upright.
- Cock or plug: A cone-shaped plug moves to one side when a wheel or handle is turned.
- Gate or sluice: Metal gates are lowered across pipes, usually only capable of being fully open or fully closed.
- Globe: When turned a valve is screwed in, such as with a tap.
- Needle: A long, sliding needle regulates fluid flow, such as in central heating systems.
- Spool: Valves slide backwards and forwards to direct fluid flow around a pipe circuit, such as in hydraulic systems.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
- Actuator.
- Building heating systems.
- Drainage.
- Ductwork.
- Flange.
- Gasket.
- Key qualities of springs.
- Manhole.
- Mechanical, electrical and plumbing MEP.
- Pipework.
- Pipework defects, ventilation and airflow rates.
- Pumps and dewatering equipment.
- Radiator.
- Sewer construction.
- Thermal storage for cooling.
- Water engineering.
- Water transfers and interconnections.
Featured articles and news
How Lidl has been actively working to reinforce their brand through sustainability.
Association of British Insurers describe full-scale cladding tests as 'utterly inadequate'.
This article examines the changing policy commitments and evolving definitions of the zero carbon home.
Researchers believe they may have created a 'game-changing' new form of concrete using graphene.
Grouting refers to the injection of materials into a soil or rock formation to change its physical characteristics.
Part of Designing Buildings Wiki, BREEAM Wiki will advance knowledge sharing for the BRE family of sustainability tools.
Iron, glass and wood underfoot
From the decorative to the utilitarian, and from the photographed to the forgotten.
New BRE book considers the progression from project-based knowledge creation to whole-life urban knowledge management.
This CIOB article explores the concept of value in building design and construction.
Rogers Stirk Harbour + Partners' release new images of soon-to-open 3WTC tower in New York.
A document can be called a bond or a guarantee. Does the name matter and what is the difference between them?
New briefing note is launched focusing on increasing knowledge of housing that promotes health and wellbeing.