How is nozzle pressure typically expressed?

Nozzle pressure is typically measured in pounds per square inch (psi) because it quantifies the force that water exits from the nozzle in relation to the area it occupies. This measurement is critical in firefighting and other fluid dynamics applications as it directly affects the reach and effectiveness of the water stream. Higher nozzle pressure usually means a better ability to project the water over greater distances or to overcome obstacles, making it an essential parameter in determining how effectively a nozzle can operate under various conditions.

The other measurements, such as pounds per square foot, pounds per cubic inch, and pounds per gallon, do not accurately relate to the specific pressure exerted by the water exiting the nozzle, which is why they are not appropriate for expressing nozzle pressure.