Mistakes to Avoid When Transitioning from High to Low-Pressure Nozzles

As fire departments update their equipment, many are choosing to move from high-pressure to low-pressure firefighting nozzles. If you find yourself on one of those departments, you know that this choice can significantly impact your operations. We’re here to make sure you have the information you need to make an informed decision and execute the change smoothly.

In this article, we will explore the similarities between high and low-pressure nozzles, advantages and disadvantages of each, and discuss the common mistakes you can avoid when switching over.

What Does High-Pressure and Low-Pressure Mean?

In firefighting, a high-pressure nozzle is one that operates at 100 PSI (7 bar). For many years this was standard in the United States and is still popular around the world.

A low-pressure nozzle is one that operates at 50-75 PSI (3 – 5 bar). The lower pressure nozzle has become much more popular in the United States over the last few years for several reasons. These reasons can include safety concerns, lessening firefighter fatigue, and hose line improvements.

Similarities Between High-Pressure and Low-Pressure Nozzles 

Before we explore the advantages and disadvantages of each nozzle, let’s take a moment to explore the similarities between these nozzle options.

  1. High-Pressure and low-pressure combination nozzles can be fixed gallonage, selectable, or automatic, giving you plenty of options when choosing your nozzle type.
  1. Both nozzle pressures can move the same amounts of water, depending on the gallonage of the nozzle you select.
  1. The stream quality and reach are comparable for typical firefighting scenarios.
  1. Both styles will put out a fire when paired with proper training and firefighting techniques.

Advantages and Disadvantages of High-Pressure Nozzles:  

High-pressure nozzles have their positive and negative attributes that you should consider before deciding if they are right for your crew. In Europe and other countries around the world, these nozzles remain popular for departments that wish to use higher pressure and lower volumes of water during a fire.

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Advantages of High-Pressure Nozzles 

A high-pressure nozzle’s increased water pressure and velocity supply a powerful water stream that can penetrate through thick materials and reach distant fires. This enables you to extinguish flames in challenging situations.

Disadvantages of High-Pressure Nozzles 

It is important to acknowledge that high-pressure nozzles come with certain downsides. The higher pressure does mean firefighters need to handle more reaction force from the nozzle. This can lead to quicker fatigue and a higher risk of injury.

Advantages and Disadvantages of Low-Pressure Nozzles:  

Low-pressure nozzles also have their positives and negatives that need to be considered. Notably, lower pressure nozzles have become more popular in the United States as departments opt for easier handline nozzle management.

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Advantages of Low-Pressure Nozzles 

Low-pressure nozzles offer improved control and safety for firefighters, especially in confined spaces or situations where a high-pressure nozzle would be challenging to handle. The reduced force of the water stream also decreases the likelihood of injury and can limit firefighter fatigue since you are no longer fighting as much force from the nozzle.

Another benefit of low-pressure nozzles is the ability to use additional hose length with eductors. The back pressure limitation of 65% inlet pressure when using an eductor must be balanced between nozzle pressure and friction loss. When the nozzle pressure is lowered, more friction loss can be allowed, making additional hose length possible. This can be particularly useful when using 250 or 350 gpm eductors with 2.5” hose to supply ground monitors.

Disadvantages of Low-Pressure Nozzles 

Low-pressure nozzles do have reduced reach from the higher-pressure nozzles. While this may not be an issue with interior firefighting, it is something to remember during your operations as it could affect your effectiveness on the fire ground.

Another disadvantage is that lower pressure can increase the potential for hose kinks. Switching to low-pressure nozzles without evaluating or upgrading your hose could cause considerable difficulty with hose maneuverability.

Mistakes to Avoid When Switching from High-Pressure to Low-Pressure Nozzles: 

  1. Forgetting about the hose line: Moving to lower pressure can affect nozzle handling if the hose line is not accounted for. If you choose to move to lower pressure nozzles, ensure the hose you are using is compatible with those pressures. Incompatible hose can lead to kinks and difficult to maneuver hose lines that can drastically impact your crew’s effectiveness.
  1. Not adjusting your pump pressure appropriately: Transitioning from high-pressure to low-pressure nozzles requires careful adjustment of your pump discharge pressure. When switching over, ensure your crew receives proper training on adjusting and calibrating the water pressure accordingly.
  1. Not providing adequate training to firefighters: Transitioning to a new type of nozzle requires comprehensive training for all firefighters involved. Familiarity with the differences between high-pressure and low-pressure nozzles, understanding their advantages and limitations, and hands-on training for proper nozzle operation are critical.
  1. Ignoring the importance of proper maintenance and inspection: Regardless of the nozzle type used, regular maintenance and inspection of your firefighting equipment is vital. When transitioning nozzles, you should ensure that the necessary maintenance protocols are followed.

What About Dual Pressure Nozzles? 

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Dual pressure firefighting nozzles are a unique middle ground between high-pressure and low-pressure options. With a dual pressure nozzle, you can choose which mode to work in. This gives you the advantage of both options on the fire ground. However, this type of nozzle does require effective communication between the firefighter handling the nozzle and the pump operator. As with any equipment, proper training and practice are essential to using it correctly.

Interested in a dual pressure option? Explore dual pressure nozzles here


In firefighting, selecting the right firefighting nozzle can significantly affect the outcome of operations. Transitioning from high-pressure to low-pressure nozzles presents a series of advantages and challenges that you must navigate effectively. Understanding the advantages and disadvantages of each nozzle type is crucial to make informed decisions based on the specific firefighting scenario.

Ultimately, the key lies in striking a balance between the advantages offered by each nozzle type and your specific firefighting requirements. Be sure to carefully assess your needs, evaluate the advantages and disadvantages, and equip your personnel with the right knowledge and tools.