What is the formula for Smooth Bore Nozzle Reaction?

The formula for Smooth Bore Nozzle Reaction is derived from the principles of fluid dynamics and is essential for understanding the forces at play when water is discharged through a smooth bore nozzle. The correct formula expresses the nozzle reaction in terms of the diameter of the nozzle and the nozzle discharge pressure.

In this case, the formula is 1.57 x d² x NP, where 'd' is the diameter of the nozzle in inches and 'NP' represents the nozzle pressure in pounds per square inch (psi). The factor of 1.57 is derived from the conversion of the flow rate into the force exerted by the water exiting the nozzle. This factor accounts for the specific weight of the water and serves to convert the pressure units to a force.

The application of this formula is crucial for firefighters and operators, allowing them to calculate the reactive force that will be experienced at the nozzle when water is being discharged. Understanding this reaction force is vital for proper positioning and control of the nozzle, ensuring operator safety and effective firefighting operations.

Other formulas may involve different coefficients or variables that do not accurately reflect the true relationship between nozzle diameter, discharge pressure, and resulting reaction forces when using smooth bore nozzles.