How a Properly Refilled DLP System Prevented Major Fire Incident

In fire safety, prevention often hinges on preparation. One of the most overlooked yet vital components is regularly refilling the fire suppression system—especially those using DLP (Direct Low Pressure) tubing. A single oversight can lead to irreversible damage, but as this real-world case study shows, a properly refilled DLP system can mean the difference between disaster and recovery.

In this blog, you’ll learn about an actual incident where a well-maintained DLP fire tubing system activated precisely when needed and prevented a major fire from escalating. We’ll explore what happened, why the refill mattered, and what your business can learn from it.

What Is a DLP Fire Tubing System?

A DLP fire tubing system is a self-activating fire suppression solution that uses heat-sensitive tubing installed inside or around fire-prone equipment. When a fire breaks out, the tubing bursts at the hottest point, releasing a clean agent directly onto the fire source—without needing external activation or electricity.

These systems are used in:

• Electrical control panels

• Data centers

• Commercial kitchens

• CNC machines

• Server rooms

• Enclosed industrial cabinets

The Incident: Electrical Fire in a Control Cabinet

Location: Manufacturing Facility, Ohio, USA
Equipment at Risk: Automated Packaging Line
Cause: Electrical short circuit in PLC (Programmable Logic Controller) unit
Date: February 2025
System Used: Pre-installed DLP fire tubing with FM-200 clean agent
Previous Service: Full refill and maintenance – 3 months prior

Timeline of Events

• 12:44 AM: Sensor picks up heat rise in a packaging line control cabinet.

• 12:45 AM: Electrical short triggers sparks, igniting nearby cable insulation.

• 12:45:06 AM: DLP tubing bursts at the ignition point.

• 12:45:08 AM: FM-200 agent is discharged immediately onto the flames.

• 12:45:30 AM: Fire suppressed before spreading to adjacent machinery.

• 12:48 AM: Safety team inspects cabinet; minor soot, no structural damage.

How the Refill Saved the Day

Three months prior to the incident, the facility's fire safety manager scheduled a routine DLP tubing system inspection and refill. During the service:

• Pressure levels were recalibrated.

• The FM-200 cylinder was topped off to full capacity.

• Tubing routing was reviewed and slightly adjusted.

Had this refill not taken place, the system may have been undercharged or failed to activate properly—leading to significant fire damage and downtime.

Benefits of Timely Refilling: Case Summary Table

Fire Safety Compliance: A Hidden Hero

In this case, the facility not only followed internal protocols but also complied with:

• NFPA 2001: Clean Agent Fire Extinguishing Systems

• ISO 14520: Gaseous Fire-Extinguishing Systems

• Local Fire Code: Mandated quarterly inspection and annual refill

Being compliant wasn’t just about avoiding fines—it literally saved the operation.

Why Refill Intervals Matter

Like all pressurized systems, DLP suppression agents can leak or depressurize over time, even without activation. This makes regular refilling critical for:

• Restoring cylinder pressure to recommended levels

• Preventing agent degradation

• Ensuring quick, even discharge

• Avoiding sensor or nozzle clogging

Most manufacturers suggest annual refilling or sooner if the system is activated.

What Could Have Gone Wrong?

If the refill was skipped or delayed:

• The tubing may have burst, but no suppressant would have discharged.

• The fire could have spread to the entire control cabinet.

• Nearby machinery, valued at over $50,000, could have been lost.

• The company may have faced production delays, lawsuits, and lost clients.

All this was prevented by a simple, scheduled refill.

Preventive Maintenance Checklist

To ensure your DLP system is ready when needed, follow this checklist:

Monthly:

• Inspect tubing for discoloration or damage

• Check cylinder pressure gauge

• Ensure nozzles are clear

Quarterly:

• Conduct system functionality test

• Review system logs and any error alerts

Annually:

• Refill suppressant cylinder

• Pressure-test the system

• Replace aging tubing (if over 5 years old)

• Recalibrate sensors and control panel interfaces

Lessons Learned from the Incident

1. Don’t wait for a fire to test your system.

2. Budget for refills just like you do for insurance.

3. Train staff to recognize refill indicators.

4. Automate reminders for inspections and service.

5. Document all service history to avoid liability.

Real-World Takeaway

In the Ohio incident, a properly refilled DLP system not only extinguished the fire but did so automatically, without requiring human intervention. It acted in seconds—faster than a manual extinguisher or sprinkler system could be deployed.

This event underscores the importance of routine refilling as part of your fire safety strategy. It’s a small cost with massive benefits.

Conclusion:

Fire safety isn’t just about alarms and extinguishers—it’s about maintaining every piece of your suppression system. As this case proves, a properly refilled DLP system isn’t just a regulatory checkbox—it’s a proven fire prevention solution.

One refill. One decision. One system standing between a small spark and a major disaster.