How is discharge pressure calculated for the 1 ¾" courtyard hose?

Discharge pressure for a firefighting hose is critical for ensuring adequate water flow to the nozzle during an operation. In this scenario, the correct method for calculating discharge pressure for the 1 ¾" courtyard hose includes both the friction loss from the 1 ¾" hose itself and the additional friction loss from the 2 ½" hose, as well as the elevation loss if applicable.

When calculating discharge pressure (DP), it is important to account for the pressure needed to overcome friction losses not just from the hose you are primarily considering, but also from any upstream components that contribute to the total friction loss, such as another hose diameter in parallel or series. Therefore, incorporating the friction loss for the 2 ½" hose along with the friction loss for the 1 ¾" hose provides a more complete understanding of the dynamics involved in the firefighting operation, especially in situations where multiple hose sizes are utilized.

Additionally, adding elevation loss (EL) ensures that any height difference between the supply source and the discharge point is compensated for, which is critical in maintaining water pressure at the nozzle level. Consequently, by blending these components, the discharge pressure reflects a more accurate and functional figure, providing an essential metric for fireground operations.