Math
This four-part equation is used by AFD Engineers to determine engine pressure.
What is EP = NP + FL ± EL + APP?
The Elkhart Brass Chief XD fixed-gallonage handline nozzle operates at this nozzle pressure.
What is 50 psi?
When the nozzle is above the pump, elevation pressure is added. When the nozzle is below the pump, it is treated this way in the engine-pressure equation.
What is subtracted, or treated as negative?
This foam class is generally intended for ordinary combustible fuels, while the other is intended for flammable-liquid incidents.
What are Class A and Class B foam?
The apparatus foam-selector lever is normally stored in this position.
What is Class A?
Regardless of the hydraulic calculation, AFD Engineers are instructed never to exceed this engine pressure.
What is 250 psi?
AFD smooth-bore handline nozzles are operated at this nozzle pressure.
What is 50 psi?
AFD estimates elevation pressure using this rule for every foot of vertical elevation.
What is 0.5 psi per foot?
AFD's Class A foam is normally started at this concentration and adjusted wetter or drier as needed.
What is 0.3%?
AFD's minimum Class B foam-solution application rate is this many gallons per minute per square foot for 15 minutes.
What is 0.10 gpm per square foot?
From a draft, a fire pump will produce 100% of its rated capacity at this pressure.
What is 150 psi?
The TFT QuadraFog nozzle operates at this pressure during normal operation and is set to this flow for foam-eductor operations.
What are 100 psi and 95 gpm?
In the friction-loss equation FL = C × Q² × L, this value is the coefficient for 3-inch hose.
What is 0.9?
Class A foam concentrate begins to gel below approximately this temperature.
What is 26°F?
Foam Pro and Advantus onboard systems automatically inject concentrate into the water stream to maintain approximately this Class A percentage range.
What is 0.3% to 0.5%?
The calculated engine pressure for a preconnected handline may differ from this pressure marked directly on the apparatus because each discharge is flow tested.
What is the labeled pump-panel discharge pressure?
A 1⅛-inch smooth-bore handline tip flows approximately this many gallons per minute at its standard nozzle pressure.
What is 265 gpm?
For field calculations involving 3-inch hose, AFD simplifies the friction-loss equation to this.
What is FL = Q²?
Because of carcinogenic and environmental concerns, AFD reserves AFFF for these types of incidents and prohibits its use for training.
What are serious incidents involving immediate life threats or significant property values threatened?
AFD's common portable Class B eductor setup uses a 200-foot, 1¾-inch preconnect with this nozzle set to this flow.
What is a TFT QuadraFog set to 95 gpm?
An Engineer must supply a nozzle requiring 50 psi, with 35 psi friction loss, 20 psi elevation pressure, and no appliance loss. This is the required theoretical engine pressure.
What is 105 psi?
A 2-inch smooth-bore master-stream tip operated at 80 psi delivers approximately this flow.
What is 1,000 gpm?
A nozzle is operating 60 feet above the pump. Using AFD's field calculation, this much elevation pressure must be added.
What is 30 psi?
Mixing these two types of foam concentrate can cause the mixture to gel and harden inside the lines.
What are Class A and Class B foam concentrates?
A 1,000-square-foot Class B fuel spill requires a 0.10 gpm-per-square-foot application rate using 1% foam for 15 minutes. This much foam concentrate is required.
What is 15 gallons?