Water Flow

How Does an Automatic Firefighting Nozzle Work?

Authored By
Date September 12, 2018
Date September 12, 2018
Share mail

Sketched on a napkin in 1968, the automatic fire nozzle is the youngest nozzle type you’ll encounter in the fire service. So, how do they work and what makes them “automatic?” Let’s find out! 

What is an Automatic Firefighting Nozzle?  

An automatic nozzle is a variable flow, constant pressure firefighting nozzle. This means that your automatic will maintain its pressure within its flow range. It does this with a spring-loaded baffle. 

If your PDP increases and sends more flow, the baffle moves forward to create a larger opening and maintain its rated pressure. If the flow rate decreases the baffle will move back to create a smaller opening. 

Is the Flow and Pressure Curve Different? 

Yes! Because the automatic nozzle adjusts to maintain its rated pressure, the flow and pressure curve looks much different than that of the smoothbore, fixed, or selectable gallonage nozzles.  

Keep Learning 

You can learn more about smooth bore nozzles, selectable nozzles, and fixed flow nozzles with these learning hub articles!