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Fire hydrant

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A fire hydrant is a vital tool for fire protection. It acts as a connection point where firefighters can tap into a water supply.

Downtown Charlottesville fire hydrant
Downtown Charlottesville fire hydrant

These devices are found in many different forms around the world. Some hydrants sit above the ground as pillars. Others stay hidden under heavy metal covers in the street.

Cross-sectional illustration of a typical dry-barrel hydrant
Cross-sectional illustration of a typical dry-barrel hydrant

In many places, they are essential for keeping communities safe. They allow for a fast and powerful way to fight fires.

To use a hydrant, a firefighter must follow specific steps. First, they attach a hose to the hydrant using a threaded or quick connection.

Hydrantandcb
Hydrantandcb

Next, they open a valve to allow the water to flow. This water comes out with great pressure. The pressure depends on the size and location of the water main. Firefighters often connect the hose to a fire engine to boost this pressure. They must be careful not to open the valve too fast. Opening it too quickly can cause a water hammer that damages pipes.

People have used underground hydrants for a long time. In Europe and Asia, they have been used since at least the 18th century. The pillar-type hydrants we see above ground were invented in the 19th century.

Dry Fire Hydrant in East Haven, Vermont April 2018
Dry Fire Hydrant in East Haven, Vermont April 2018

In the United States, many hydrants have a large "steamer" outlet. This name comes from the past when they supplied steam-powered pumps. Today, firefighters must be very fast during training. They often learn to connect to a hydrant in under one minute. Time is a critical factor when a fire is burning.

Hydrants come in two main types based on the weather. In cold areas, people use dry-barrel hydrants.

Cross-sectional illustration of a typical dry-barrel hydrant
Cross-sectional illustration of a typical dry-barrel hydrant

Most of the hydrant stays below the frost line to prevent freezing. A drain valve lets water out of the barrel when it is not in use. In warmer areas, wet-barrel hydrants are used. These keep water in the barrel at all times.

Hydrantandcb
Hydrantandcb

In the U.S., hydrants are often painted chrome yellow. The colors on the caps tell firefighters how much water is available. Blue caps mean a very good flow of over 1500 gallons per minute. Red caps mean the flow is low, at less than 500 gallons per minute.

Hydrants are part of the water system we use every day. While they are for emergencies, they have other uses too. Some construction workers use permits to get water from them.

Reduced pressure zone device connected to a fire hydrant at a construction site
Reduced pressure zone device connected to a fire hydrant at a construction site

In the summer, some people use them to cool off. In 1896, a commissioner in New York City even opened hydrants to help during a heatwave.

Philadelphia fire hydrant
Philadelphia fire hydrant

You might also see them used by street sweepers to fill tanks. They are important tools that help manage water in our cities.

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🖼️ Images & Media (7)
File:Downtown Charlottesville fire hydrant.jpg
Downtown Charlottesville fire hydrant.jpg
File:Philadelphia fire hydrant.jpg
Philadelphia fire hydrant.jpg
File:Reduced pressure zone device connected to a fire hydrant at a construction site.jpg
Reduced pressure zone device connected to...
File:Cross-sectional illustration of a typical dry-barrel hydrant.png
Cross-sectional illustration of a typical...
File:Hydrantandcb.jpg
Hydrantandcb.jpg
File:Kawaii fire hydrant cover in Tokyo, Shinbashi.jpg
Kawaii fire hydrant cover in Tokyo, Shinbashi.jpg
File:Dry Fire Hydrant in East Haven, Vermont April 2018.jpg
Dry Fire Hydrant in East Haven, Vermont...
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