Fire Fighting Spray Nozzle


Nozzles play an important role in fire protection systems. The nozzle you choose can impact the application rate, type stream and heat absorption.

In the factory example above, if the plant was not equipped with fire fighting spray nozzle, the flames could spread rapidly and destroy the facility. This would cause a loss of production and risk the lives of employees.
High Flow Rate

Firefighting nozzles are designed to aid in “Fire Suppression” (extinguishment) by providing the right amount of water, in the correct form, at the right time. The size of the orifice creates a restriction that changes water pressure into velocity, which provides the reach necessary to penetrate the fire thermal column.

However, high nozzle reaction forces can severely limit controllability and deployment. For example, one large county fire department has decided to change from a combination nozzle with a 7/8-inch smooth bore tip at 100 psi to an 11/8-inch smooth bore tip at 50 psi to reduce nozzle reaction force and provide more controllable 1 3/4-inch attack handlines.
Straight Stream

Smooth bore nozzles produce a solid stream of water that stays the same shape as it exits the nozzle. They provide greater reach and penetration to the fire’s seat than nozzles with broken or fog streams. Stack tips can be added to straight tip nozzles to increase pressure and narrow or widen the flow for better control and more efficient use of water.

NFPA identifies four qualities that impact the survival of attack water: shape, volume retention, impact dispersal and fire heat absorption. Using a spray pattern provides three of those components, while a fog pattern provides two. Increasing the Application Rate (gpm) will help achieve the remaining one.
Fog Stream

While some fire departments still use fog stream nozzles, other crews have moved on to combination nozzles. These nozzles are more versatile and support multiple call types.

Fog nozzles expel a dispersed stream of water droplets that can be quickly converted into steam to absorb heat. This helps them to ventilate a room or take heat out of an environment.

However, some firefighters say that using fog nozzles limits flexibility as conditions change. For example, if an operator rotates the nozzle from a fog pattern to a straight stream pattern, the flow rate decreases because it uses a different orifice size. This can be frustrating.
Constant Gallonage

Smooth bore nozzles require the least amount of training for both the pump operator and firefighter. Fog nozzles require more training because of the various spray patterns characterized by this type of nozzle.

Constant gallonage nozzles (also called adjustable-pattern spray nozzles) maintain a constant flow rate through a range of patterns—from straight to wide fog—when given a designated pressure. This nozzle style is designed to ensure stream reach with a self-adjusting component that keeps nozzle pressure steady.

Nozzle reaction determines the manageability of a hoseline and staffing needs. The lower the reaction force, the easier it is to operate and extend a hoseline.
Select Gallonage

Firefighters need a nozzle that will deliver the right amount of water to stop the chemical reaction that creates fire. Nozzles with a select gallonage feature allow firefighters to choose their desired flow rate for each application.

This feature makes it easier to use a nozzle without the need for additional personnel on the line. It also helps reduce fatigue for firefighters who must handle large amounts of water and hose line pressure.

Nozzles with a select gallonage also allow firefighters to adjust the rated pressure of their nozzle. This helps ensure that the nozzle’s stream always looks good regardless of its flow rate.
Adjustable Gallonage

An adjustable gallonage fire fighting spray nozzle is similar to the constant gpm nozzle but allows firefighters to manually select orifice sizes, ranging from wide fog to straight stream. This type of nozzle is easy to use and works well with foam eductors, according to Stewart.

Choosing the right handline nozzle for your needs begins with knowing the expected flow rate based on normal engine pressures and hose lays. It’s also important to consider whether the nozzle will be used in other applications that may require different flows.

If you need quality stream performance and basic flow options, the combination pattern nozzle from Task Force Tips is a great choice. This nozzle can be switched from straight to fog with a simple turn of the bumper adjustment.

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