First let’s get a couple terms straight. When you think nozzle, you might think of the end of the hose where water is expelled. In the case of firefighting, the nozzle is a device attached to the end of a fire hose that directs, shapes and regulates the flow of the water or fire fighting agent pumped into the hose. It may have a control valve and can also be referred to as a branch pipe. The “nozzle tip” is the part o the hose that forms and controls the stream of water as it leaves the hose. So when you talk about fog nozzles, smooth bore, solid, etc you are talking about the nozzle tip.
There is a variety of different nozzles, or rather nozzle tips used in the fire service. Some common ones would be the smooth bore and and the fog nozzle. There are also automatic (?) nozzles.
A smooth bore nozzle is one of the oldest types of nozzles in the fire service. It operates best at about 50-80 pounds per square inch The smooth bore nozzle provides a steady stream that will easily penetrate through flames to the material that is burning.
Another type is the fog nozzle. A fog nozzle breaks the stream of water into tiny droplets. It operates best at about 80 – 100 pounds per square inch. By adjusting the nozzle tip, you can adjust how narrow or wide the flow of water is. Generally there are three types of flow that come from a fog nozzle:
- Straight stream for long reach
- Narrow-angle cone for advancing an attack line into a structure or fire room
- Wide-angle cone for protection and ventilation.
The fog nozzle can cover a wider area however it falls short of the smooth bore nozzle when it comes to the distance the water can travel, partly due to the air introduced into the water column.
There are a variety of specialty nozzles that are used. One that I will mention here is the foam eductor. This is a specialized nozzle tip used to apply foam. These nozzle are usually a relatively large bells shaped cone and operate under a lower PSI rating than do the smooth bore and fog nozzles.
Firefighter Nation has an article, from 2012 that talks about the pros and cons of different nozzle types.
Join me on an A to Z Journey of firefighting tools throughout the month of April. I appreciate feedback. Please keep in mind that I am not (nor do I pretend to be) a firefighter or a member, either volunteer or paid, of the fire service. My purpose here is to pass on knowledge that I find in hopes to both bring awareness to the fire-service and to help those in the profession do their job safer and better.