- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 21 Mar 2018
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.
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.
 Find out more
 Related articles on Designing Buildings Wiki
- Building heating systems.
- Key qualities of springs.
- Mechanical, electrical and plumbing MEP.
- Pipework defects, ventilation and airflow rates.
- Pumps and dewatering equipment.
- Sewer construction.
- Thermal storage for cooling.
- Water engineering.
- Water transfers and interconnections.
Featured articles and news
A vision for digital highways
Finding stone to conserve historic buildings.
If it is not planned properly even a simple activity can kill.
A disgruntled or ignored stakeholder can easily derail your hard work.
Next generation cementitious materials
Still going strong...one of the great buildings of the 20th century.
Review of the bible for heritage assets and their management.
The David Lloyd Lymington Sports Village was 'Commended' in CIAT's 2018 AT Awards.
How do we make the smart city a reality?
Sir Nicholas Grimshaw has been awarded the UK’s highest honour for architecture.
Protecting the construction industry from Brexit.
Conceiving buildings collaboratively, testing them virtually.
Effective collaboration in post-disaster response and recovery