As a wildland firefighter, you must have a range of fire hose nozzles to suit the variety of different problems and conditions you may encounter while on the job. While a smooth-bore nozzle may be ideal for certain situations, other scenarios may call for an automatic spray nozzle. Ultimately, there is no one-size-fits-all solution. Be familiar with the many different fire hose nozzles available so that you’re prepared for any situation. To learn more about some of the different types of fire hose nozzles, continue reading.
Smooth-Bore Nozzles
Smooth-bore nozzles, a type of manual nozzle, have a simple, cylindrical design that doesn’t consist of any internal parts to facilitate the control of gallonage or pressure. They are known for producing the greatest reach/gpm combination of all other wildland firefighting nozzles. Despite producing the greatest reach/gpm combination, they also use the lowest engine pump pressures.
Additional benefits of smooth-bore nozzles include their ability to easily pass debris because of their simple design, easy operation, and low reaction force. Plus, smooth-bore nozzles are also the most inexpensive fire hose nozzle option.
In terms of their stream, smooth-bore nozzles exhibit a solid, consistent water pattern. The pattern is compact and allows a substantial amount of water to be transported to the seat of the fire. As a result of their solid stream, smooth-bore nozzles provide maximum reach and penetration to the fire’s seat.
However, the solid stream of smooth-bore nozzles isn’t always beneficial. In order for the water from the smooth-bore nozzle to absorb as much heat as nozzles with broken or fog streams, the water pattern of the smooth-bore nozzle must be broken up by nozzle movement.
Constant Gallonage Spray Nozzles
Another different type of fire hose nozzle is the constant gallonage spray nozzle. A constant gallonage spray nozzle is a type of firefighting nozzle that discharges water at a consistent gpm, which is predetermined by the manufacturer, provided that they are issued the required nozzle pressure. In other words, it issues a consistent, unchanging amount of water.
Key benefits of constant gallonage nozzles include their ease of use, ample reach and foam production, and variable stream, which can be straight stream, narrow fog, and wide fog. In addition, constant gallonage nozzles are also often a more economical option in comparison to other nozzle versions, such as variable gpm and automatic nozzles.
While the flow of a constant gallonage spray nozzle is constant, the water pattern can be adjusted to a variety of different options at various nozzle pressures. For example, a constant gallonage spray nozzle can be adjusted to have several different patterns ranging from a straight stream to a wide spray stream. When changing patterns, the orifice size of the constant gallonage nozzle remains the same, which allows it to retain a constant gpm.
Typically, constant gallonage nozzles come in a variety of nozzle pressures, such as 50, 70, or 100 psi. The higher the nozzle pressure, the more water that it issues, which can make a high psi nozzle quite beneficial in many situations. That being said, a higher psi also creates the potential for more nozzle reaction—the pound-force (lbf) of pushback that results from the combined volume and pressure leaving the nozzle—which is an important factor to consider when choosing a wildland fire hose nozzle. To reduce engine wear caused by nozzle reaction, it can be advantageous to opt for a more low-pressure version.
Potential downsides to be aware of when opting for constant gallonage nozzles include their larger and bulkier design and their high number of moving interior parts, which can make it more challenging to pass debris and potentially lead to water deposit buildup or mechanical failure. In addition, a constant gallonage spray nozzle has more moving internal components than a smooth-bore nozzle. The presence of such components may increase the potential for the constant gallonage spray nozzle to experience mechanical failure or water deposit buildup. As such, proper maintenance practices must be carried out in order to keep the nozzle operating properly.
Automatic Spray Nozzles
Also known as constant pressure spray nozzles, automatic spray nozzles refer to a type of adjustable fire nozzle that has variable water patterns and maintains a relatively consistent pressure as flow rates increase or decrease. Examples of potential water patterns that an automatic spray nozzle can output include straight stream, narrow fog, and wide fog.
As flow rates change, the stream of an automatic spray nozzle has the unique ability to maintain its proper shape, retain the designated nozzle pressure for the gallonage, and obtain optimum reach with the water provided. The automatic spray nozzle is able to accomplish these objectives because of the presence of a preset internal spring mechanism. Depending on the pressure of the water, the spring will either expand or contract. Greater amounts of pressure cause contractions that allow the nozzle to open more, while smaller amounts of pressure cause the spring to expand, subsequently tightening the nozzle.
While automatic spray nozzles have several benefits, such as constant nozzle pressure, variable streams, and ease of use, they also have a few downsides that should be taken into consideration. For example, if the pressure of the hose is too low, then the nozzle may not open sufficiently, which will result in a weak stream. In some cases of extremely low pressure, the nozzle may not even open at all. On the other hand, extremely high pressures can result in a more inconsistent stream, which makes the nozzle harder to control. Additionally, like all hoses with several different internal components, it is important to maintain the nozzle properly to prevent the interior mechanisms from breaking.
The Supply Cache is committed to providing wildland firefighters with the gear and equipment you need in order to effectively combat fires and stay safe on the job. When it comes to fire nozzles, we know that you need a variety of different options in order to combat whatever nature throws at you. As such, we stock an extensive variety of reliable, high-quality forestry fire nozzles—from constant flow firefighting nozzles to adjustable fire nozzles.
