The pressure remaining in a water distribution system when water is flowing is the ________ pressure.

The term that describes the pressure remaining in a water distribution system while water is actively flowing is known as residual pressure. This pressure is critical because it indicates the ability of the system to deliver water during firefighting operations. Residual pressure is measured when water is being drawn from the system, which can occur during firefighting efforts or when multiple outlets are in use.

Understanding residual pressure is essential for firefighters because it ensures there is enough pressure to effectively deliver water to extinguish fires. This pressure can be influenced by various factors, including the size of the main, the number of users drawing water at the same time, and the design of the distribution system. When firefighters arrive on scene, they utilize pressure gauges to assess residual pressure, allowing them to determine the adequacy of water supply for firefighting.

In contrast, static pressure refers to the pressure in the system when no water is flowing. Dynamic pressure refers to the pressure in a flowing system, but the residual pressure is specifically the measurement relevant to how much pressure is left when water is actively being used. Understanding the differences between these terms is crucial for effective water supply management during firefighting operations.