Saponification is best described as
- Dry chemical melting into a sticky coating on glowing wood embers
- Alkaline agent reacting with hot fat to form a soapy foam layer
- Carbon dioxide turning to dry ice in the horn
- Foam concentrate mixing with air at the nozzle
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B. Alkaline agent reacting with hot fat to form a soapy foam layer
Alkaline wet chemical reacts with hot cooking fat to make a soap-like foam that seals the surface, while the water in the agent cools the oil. The sticky coating describes monoammonium phosphate on Class A fuel.
Reference: NFPA 10: extinguisher types and agents
The fire tetrahedron adds which fourth element to the fire triangle of fuel, heat and oxygen?
- An uninhibited chemical chain reaction
- A continuous source of ignition
- A minimum fuel vapor pressure
- A confined space to hold the heat
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A. An uninhibited chemical chain reaction
Flaming combustion needs fuel, heat, an oxidizer and a self-sustaining chemical chain reaction. Dry chemical and halon work mainly by breaking that chain. An ignition source starts a fire but is not needed to keep it going.
Reference: Fire chemistry: fire tetrahedron
What does pre-engineered mean for a kitchen suppression system?
- It is custom calculated by an engineer for each kitchen
- It is assembled at the factory and cannot be altered
- It is designed by the local fire marshal's office
- It is installed within the limits of its listed manual
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D. It is installed within the limits of its listed manual
Nozzle types, pipe lengths, flow points and appliance coverage were all fire tested, and the installer must stay inside those listed limits. No hydraulic calculation is done, but the limits cannot be exceeded.
Reference: NFPA 17A and NFPA 96: wet chemical systems for commercial cooking