For more than a century, firefighters have accepted one simple truth about smoothbore deck gun nozzles: If you want to change the flow, you shut down the stream, climb onto the apparatus and swap the stacked tip.
That’s just how it’s always been done. Until now.
HEN’s new Flex™ system introduces the first electronic stacked-tip nozzle for deck guns and turrets, allowing firefighters to change flow rates remotely without shutting down the stream, climbing on the apparatus and sacrificing reach.
For the first time in the history of the fire service, a master stream smoothbore can adjust flow electronically while flowing water.
But the real story behind Flex is not just electronic control.
It’s about something firefighters understand instinctively on the fireground: Water only works if it lands where it needs to.
And that idea—perfect water placement—is reshaping how master streams are used today.
Deck guns have always been the heavy artillery of the fireground. Need to knock down a large volume of fire fast? Open the deck gun.
Need to darken down a structure before committing crews inside? Open the deck gun.
But master streams have always carried a major limitation: Lack of precision.
Most traditional deck guns were designed during a time when the prevailing strategy was to simply flow as much water as possible and overwhelm the fire.
The philosophy was volume over placement. Today’s fire environment has changed that equation.
Modern fuel loads release heat faster. Structures fail earlier. And in many situations, especially during the first few minutes of an incident, water is limited to whatever is inside the tank.
When a deck gun flowing 500 or 1,000 gallons per minute is opened on tank water, the clock starts ticking immediately.
Five hundred gallons can disappear in seconds. And when that water is gone, suppression stops.
The question facing firefighters today isn’t just how much water we can flow. It’s how effectively we can place it.
Recent fireground research and operational experience have reinforced a concept many seasoned firefighters have long understood.
Extinguishment is driven by heat absorption and heat absorption depends on water reaching the burning fuel.
Large droplets that reach the seat of the fire absorb far more heat than small droplets that evaporate in the air column.
This is why smoothbore streams remain one of the most effective suppression tools ever developed. Large droplets maintain momentum.
Sunny Sethi
They punch through thermal columns. They hit burning material directly. But traditional smoothbores also come with a drawback. They produce a narrow point of impact.
That means firefighters often must sweep the stream manually across a fire area to achieve coverage. What if the stream itself could cover more area without losing reach?
That question led to the development of blade-pattern nozzle technology, which reshapes a smoothbore stream into a wide, flat sheet of water composed of large droplets.
Instead of a narrow point of impact, firefighters get a wide band of water that maintains reach and penetration.
The result is dramatically improved water placement efficiency. And that principle sits at the heart of the Titan master stream platform.
Traditional deck guns require firefighters to stand on top of the apparatus to aim and operate the monitor. In poor weather, low visibility or chaotic fireground conditions, that can be both difficult and dangerous.
Sunny Sethi
The Titan system was built to change that.
Using electronic controls, operators can manage the monitor from inside the cab or through a remote pendant.
The system allows firefighters to control horizontal movement, vertical movement and stream orientation with a joystick rather than by physically moving the monitor.
This shift dramatically improves firefighter safety by keeping personnel off the top of apparatus and away from hazardous operating positions.
But the real advantage comes from the ability to precisely direct water onto the fire.
Smoothbore stacked tips are widely used on deck guns for one reason: Reach.
Large orifice openings produce powerful streams capable of penetrating heavy fire conditions. But stacked tips are fixed-flow devices. Changing flow means replacing hardware. If a crew starts with a 1,000 gallons per minute tip but decides they need to conserve water, they must:
This process takes time and exposes firefighters to unnecessary risk, especially on wet or icy apparatus surfaces. More importantly, it interrupts suppression at the exact moment crews are trying to control the fire.
Sunny Sethi
For years, firefighters asked the same question: Why can’t we adjust a stacked tip the same way we adjust a monitor?
HEN Flex answers that question. Flex introduces an electronically controlled orifice system that allows firefighters to adjust the effective stacked-tip size remotely.
Operators can select different flow configurations directly from the monitor controls, without shutting down the stream.
That means firefighters can:
All while the stream continues flowing. Flex combines this electronic orifice control with the Blade-Flex nozzle, allowing firefighters to adjust both the pattern and the flow rate simultaneously.
Need maximum reach to hit deep-seated fire? Tighten the pattern and increase the flow. Need wider coverage while protecting exposures? Open the blade pattern and reduce flow.
This level of control has never existed before in a smoothbore master stream.
Sunny Sethi
There is another problem that firefighters have quietly accepted for decades. Most apparatus operators do not actually know the flow rate coming out of a deck gun.
Pump pressure can be measured, but true nozzle flow depends on several variables:
The result is that many master streams are operated using estimates rather than precise data. Flex changes that.
The system integrates pressure sensors directly into the nozzle assembly, allowing the monitor to calculate and display real-time flow information.
Operators can see:
For the first time, firefighters running a master stream can truly know their flow.
When deploying master streams equipped with adjustable flow technology, company officers should consider several operational factors.
Water supply strategy: If operating on tank water, consider beginning with a lower flow setting to extend operational time until a sustained water supply is secured.
Placement before volume: Direct the stream onto the seat of the fire or heat-absorbing surfaces rather than flooding open air or exterior siding.
Exposure protection: Wider blade patterns can improve surface coverage when protecting exposures or cooling large areas.
Monitor positioning: Remote-controlled monitors allow the operator to choose better vantage points, improving accuracy and visibility.
Training opportunities: Real-time flow data provides valuable insight for pump operators and can help refine pump charts, tactics, and training programs.
A new era for master streams
The evolution of firefighting equipment often happens slowly. Pumps become more efficient. Hoses become lighter. Nozzles become more durable.
Sunny Sethi
But, occasionally technology appears that fundamentally changes how a tool is used.
The combination of Titan master stream platforms and the Flex electronic stacked-tip system represents one of those moments.
For the first time, firefighters can control reach, pattern and flow simultaneously from the monitor controls.
More importantly, they can do it while keeping water on the fire.
In an era where fires are growing more complex and resources are increasingly stretched, tools that maximize the effectiveness of every gallon matter more than ever.
Because on the fireground, one truth remains constant: The best stream is the one that lands exactly where it needs to.
