What is the term for the pressure at a discharge opening while water is flowing?

The term for the pressure at a discharge opening while water is flowing is flow pressure. This measurement specifically refers to the pressure present when water is actively being discharged from a nozzle or other opening, which is affected by factors such as the flow rate and the design of the system. It is essentially the working pressure that allows water to move through hoses, pipes, and nozzles, and is critical for understanding how effectively a flow will perform during firefighting operations.

Static pressure, on the other hand, describes the pressure of the water in the system when water is not flowing and does not account for the effects of movement. Kinetic energy relates to the energy possessed by the water due to its motion, rather than a direct measure of pressure. Friction loss refers to the loss of pressure that occurs as water moves through pipes or hoses due to friction against the walls, which impacts flow pressure but is not the same concept. Recognizing the distinction between these terms is vital for effective fire ground strategy and operation.