Basic Firefighter Written Practice Exam

What happens to the efficiency of water-jet patterns when using a solid stream nozzle?

1. It may create a wider spray

2. It remains fixed and does not adjust

3. It increases overall pressure

4. It reduces splashback

The correct answer is: It remains fixed and does not adjust

When using a solid stream nozzle, the efficiency of water-jet patterns remains fixed and does not adjust. A solid stream nozzle is designed to deliver water in a focused, continuous stream that maintains its shape and pressure over a distance. This type of nozzle is particularly useful for penetrating barriers such as walls or ceilings when fighting fires, as it creates a concentrated jet that does not diverge significantly. The solid stream is highly effective for reaching the seat of a fire since it minimizes the surface area of water exposed to the air and allows for better penetration into hot gases, enhancing cooling and fire suppression efforts. The fixed nature of the stream means there aren't any adjustments or variations in the pattern that may occur with other types of nozzles which may produce a spray, leading to concerns about water efficiency or pressure variations. In this context, choices that suggest a change in the spray width, an increase in overall pressure, or a reduction in splashback do not accurately describe the characteristics of a solid stream nozzle, as these are more relevant to other types of nozzles.