Which tool is used to measure the velocity of water coming out of a hydrant?

The pitot tube is the correct tool for measuring the velocity of water flow from a hydrant. It works by capturing the dynamic pressure of the water as it flows and converting that pressure into a velocity reading. This is critical for firefighters to determine how much water is available for firefighting efforts since knowing the flow rate can significantly impact the effectiveness of their operations.

By positioning the pitot tube correctly at the nozzle or outlet of the hydrant, firefighters can accurately measure the speed of water leaving the hydrant, which then helps them calculate the flow rate, often expressed in gallons per minute. This information is vital for assessing the adequacy of water supply for firefighting tasks.

Other tools, such as hydraulic gauges and pressure gauges, primarily measure pressure rather than velocity. While a flow meter is also capable of measuring the volume of water flowing, it is typically not used exclusively for measuring velocity directly as the pitot tube does.