How do you calculate nozzle reaction?
The nozzle reaction is found to be: R = ρ Q 2 / A2 , where A2 is the discharge diameter, Q is the volumetric flow rate, R is the magnitude of the nozzle reaction, and r is the water density. This equation shows that the reaction is proportional to the flow rate squared, divided by the nozzle diameter.
How does a fixed Gallonage nozzle work?
With a fixed-gallonage nozzle, the stream reach will drop if the pump operator cannot meet the required pressure for the nozzle, whether the drop is from the wrong size tip, a depleted water supply, or just an incorrect engine pressure. It adjusts to the flow the pump operator delivers to it.
How are spray rates calculated?
Multiply the length of the area you plan to spray times the width. If you are using metres, then divide the product by 10,000, which is the number of m2 in a hectare (ha). For feet and acres, divide by 43,560 which is the number of ft2 in an acre (ac):
What is a fixed Gallonage nozzle?
Fixed gallonage A nozzle that provides constant gallonage with an adjustable pattern of spray from straight stream to wide fog. Benefits: Easy to use; operates in a wide range of nozzle pressures from 50 to 100 psi.
Why does FDNY use smooth bore nozzles?
In the 1970s, FDNY engine companies used combination nozzles. The solid-stream nozzle is able to extinguish the fire and to cool the surfaces and the surrounding areas sufficiently to reduce the heat without producing the large rapidly expanding volumes of steam. This significantly prevents steam burns.
What causes nozzle reaction?
Nozzle reaction is the resultant lbf of pushback from the combined volume and pressure leaving the nozzle. The only way to alter nozzle reaction is to alter the volume [gallons per minute (gpm)] or the pressure (psi).
How to calculate the nozzle reaction per minute?
How to Calculate Nozzle Reaction. Calculating the Nozzle Reaction for a 1.25-inch-Bore-Diameter Nozzle The solid bore discharge formula is gallons per minute (gpm) = 29.71 D² NP¹/². The formula can be rewritten to solve for the unknown, nozzle pressure:
How to calculate the counterweight of the nozzle?
How to Calculate Nozzle Reaction. The counterweight can be determined by calculating the nozzle pressure and then the nozzle reactive force. Use the bore diameter of the nozzle and the flow in gallons per minute to calculate the nozzle pressure. Use that to determine the nozzle reactive force (See figure 1).
How to calculate flow through nozzles and orifices?
You can find typical values in our article on discharge coefficients for nozzles and orifices. The relationships for flow rate, pressure loss and head loss through orifices and nozzles are presented in the subsequent section. These relationships all utilise the parameter
How to calculate nozzle reaction during fire engine testing?
Field personnel have requested information regarding the safest and most efficient method to counter the hose nozzle reactive force generated during annual fire engine service testing.
