Fire Nozzle Lessons

Fog Nozzles

• Fog nozzles smother fires by breaking water into tiny droplets as it rains over the fire. This supposedly creates a larger attack area, turning the water into a steam that smothers the flames. Lessons involving these nozzles should focus on the pattern of the droplets they create, the rate at which they expel water, in what situations they are effective, their design and structural characteristics, how the wide fog pattern affects firefighter safety and a demonstration of how to operate and adjust the device. Firefighters should also be allowed to demonstrate the different patterns and discuss how a fog nozzle can be used in combination with other methods or devices.

Solid Stream Nozzles

• These nozzles create a single stream of water that provides the farthest reach and the most penetration, though their scope is much narrower than that of a fog nozzle. Similar to the lesson on fog nozzles, a lesson about solid stream nozzles should discuss design, function, and operation, but it should also include information on safe use and hazards of the model. This includes the fact that solid stream designs may not provide necessary protection from rollover or flashover flames during an interior fire. As such, instructors should discuss personal protection methods and ways to avoid or combat this hazard while using the tool in an interior situation.

Water Flow Rates

• In order choose the correct nozzle for a given situation, a firefighter must also know the rate at which it sprays and whether that will be adequate to put out the fire. In a lesson about flow rates, instructors should have students define a British thermal unit (BTU, a measurement of heat), and then discuss how BTUs correlate with water needs. As long as the nozzle expels more water than the fire produces heat, the nozzle should work. In order to understand this, however, lessons should cover the characteristics of water as it changes from a liquid to a gas, how it absorbs heat and how its expansion ratio can affect the surrounding area during fire suppression in a confined space.