What is the flow rate for a 1 ¾" 75' add-on with a 15/16" SB nozzle?

The flow rate for a 1 ¾" line with a 15/16" smooth bore nozzle is determined using the relevant formulas and flow testing data. Generally, smooth bore nozzles allow for precise calculations based on the nozzle size and the pressure applied.

In this scenario, when calculating flow rates for a 15/16" nozzle, the common reference details show that at a pressure of 20 psi, the flow will be approximately 185 gallons per minute (GPM). This data aligns with accepted calculations and flow charts used in fire service training and operations, confirming that when utilizing a specific length of hose with a smooth bore nozzle, this flow rate is achievable at that pressure.

The other pressures noted, such as 30 psi, 10 psi, and 15 psi, would produce different flow rates, which may either exceed or fall short of the established rate for the 15/16" nozzle in the specified configuration. Therefore, the choice indicating 20 psi flowing 185 GPM accurately reflects the expected operational standards for equipment used within the fire service environment, supporting effective firefighting efforts.