A penstock is a

sluice Sluice ( ) is a word for a channel controlled at its head by a movable gate which is called a sluice gate. A sluice gate is traditionally a wood or metal barrier sliding in grooves that are set in the sides of the waterway and can be considered ...

gate A gate or gateway is a point of entry to or from a space enclosed by walls. The word derived from old Norse "gat" meaning road or path; But other terms include ''yett and port''. The concept originally referred to the gap or hole in the wall ...

or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and

sewerage Sewerage (or sewage system) is the infrastructure that conveys sewage or surface runoff (stormwater, meltwater, rainwater) using sewers. It encompasses components such as receiving drainage, drains, manholes, pumping stations, storm overflows, a ...

systems. The term is inherited from the earlier technology of mill ponds and

watermill A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production ...

Hydroelectric systems and dams

Penstocks for

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

installations are normally equipped with a gate system and a

surge tank A Surge tank is a water storage device used as a pressure neutralizer in hydropower water conveyance systems in order to dampen excess pressure variance. A surge tank (or surge drum or surge pool) is a standpipe or storage reservoir at the downst ...

. They can be a combination of many components such as anchor block, drain valve, air bleed valve, and support piers depending on the application. Flow is regulated by

turbine A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating ...

operation and is nil when turbines are not in service. Penstocks, particularly where used in polluted water systems, need to be maintained by hot water washing, manual cleaning, antifouling coatings, and

desiccation Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. ...

. The term is also used in irrigation dams to refer to the channels leading to and from high-pressure

sluice gates Sluice ( ) is a word for a channel controlled at its head by a movable gate which is called a sluice gate. A sluice gate is traditionally a wood or metal barrier sliding in grooves that are set in the sides of the waterway and can be considered ...

. Penstocks are also used in mine

tailings dam A tailings dam is typically an earth-fill embankment dam used to store byproducts of mining operations after separating the ore from the gangue. Tailings can be liquid, solid, or a slurry of fine particles, and are usually highly toxic and potent ...

construction. The penstock is usually situated fairly close to the center of the tailings dam and built up using penstock rings. These control the water level, letting the slimes settle out of the water. This water is then piped under the tailings dam back to the plant via a penstock pipeline.

Watermills

Penstocks are often used at mill sites to control the flow of water through the mill wheel, or to pen water into a mill pool.

Similar structures

Similar structures which are not enclosed are ''head races'' or

leat A leat (; also lete or leet, or millstream) is the name, common in the south and west of England and in Wales, for an artificial watercourse or aqueduct dug into the ground, especially one supplying water to a watermill or its mill pond. Othe ...

s (non elevated), and

flume A flume is a human-made channel for water, in the form of an open declined gravity chute whose walls are raised above the surrounding terrain, in contrast to a trench or ditch. Flumes are not to be confused with aqueducts, which are built to t ...

s (elevated).

Hydraulics

Penstocks are commonly used in water management systems such as surface water drainage and foul water sewers. Penstocks provide a means of isolation of flows and regulate the flow of water while delivering it to waste management facilities or power plants.

Landfills

Penstocks are incorporated into the surface water management systems (drainage) of many landfill sites. Attenuation lagoons are constructed in order to store storm water, limiting the discharge from the site to pre-development rate (green field rate). Penstocks are installed at the outfall from the lagoon so that in the rare event that the surface water becomes contaminated the penstock may be closed. This will have the effect of isolating the site from the watercourse, preventing contamination of the environment.{{cn, date=July 2019

References

External links

Penstock cross-sections for the Grand Coulee Dam
Aqueducts Hydroelectric power stations Water management in mining