What term describes the amount of pressure that remains in the water supply system when water is flowing?

The term that accurately describes the amount of pressure remaining in the water supply system while water is flowing is residual pressure. This measure is crucial for firefighters as it indicates the pressure that can still be extracted from the system after flow has started. It is important for assessing the availability of water when a fire is being fought, as knowing the residual pressure helps responders determine whether there is sufficient water supply to effectively combat the fire.

Static pressure refers to the pressure in the system when no water is flowing, which does not provide the necessary information about how much usable water is available during operation. Dynamic pressure, on the other hand, reflects the pressure in a flowing system but does not account for any losses or remaining pressures. Friction loss describes the reduction in pressure that occurs as water moves through hoses and other equipment due to resistance, but it does not represent the pressure left in the system once the flow has been established. Understanding these terms is essential for effective firefighting operations and resource management.