In fire fighting, the ability to quickly and accurately disperse water or foam can mean the difference between saving a business or a life. The type of fire fighting spray nozzle used can determine how far water moves, how fast, and how deeply it penetrates. It also impacts the speed at which it’s delivered and the effectiveness of its heat absorption.
Whether it’s for fire suppression systems in industrial facilities or commercial buildings, the right fire protection nozzles can make all the difference. The National Fire Protection Association’s NFPA 1964: Standard for Spray Nozzles dictates how firefighting nozzles are constructed. Generally, they must be capable of developing discharge patterns ranging from straight stream to wide fog.
There are several factors that go into deciding the best fire fighting nozzle for the job, such as the kind of fire, the type of fluid (either water or foam), and the environment in which it’s being used. Then there are considerations like whether it’s being used to drench a fire with large volumes of water or, more subtly, to use the fine mists to deprive a fire of oxygen thereby suffocating it.
These different approaches require very different nozzles, with specialist spiral nozzles being used for the drench type systems and fog nozzles for the firefighting. And there are a variety of fire fighting nozzle types, such as smooth bore, constant gallonage, automatic or constant/select gallonage, that can help achieve the right results in each case.
A fire nozzle’s spray pattern is another important factor to consider. Nozzles with a fog pattern emit a fine mist that easily turns to steam, helping take hot air out of the room and cooling it down in preparation for extinguishing the fire. Fog nozzles are also great for creating a barrier of water between an open flame and nearby structures or dispersing vapors from a gas line leak.
For a nozzle to be effective, it must absorb the heat of the flame and penetrate deep enough to stop the chemical reaction that causes fire. This is accomplished by either breaking the water into smaller droplets or by increasing the flow rate, both of which are influenced by the nozzle’s Application Rate and Type Stream. Smooth-bore nozzles produce a solid, consistent water stream and have the highest Application Rate of any type of firefighting nozzle, but they don’t absorb heat as well as those with broken or fog streams.