When fire breaks out in a data center, archive room, or control center, water and foam aren’t solutions — they’re second disasters waiting to happen. HazenFire’s Externally Pressurized FM200 system delivers clean, residue-free fire suppression with the engineering flexibility to protect even the largest, most complex facilities.
A Fire Suppression System Built for High-Value, Sensitive Environments
An Externally Pressurized FM200 Fire Suppression System is a clean agent gas fire extinguishing solution engineered for spaces where water, foam, or powder could cause catastrophic secondary damage. It uses FM200 (also known as HFC-227ea) as the extinguishing agent, paired with a separate nitrogen cylinder as the driving gas source.
You may also see this system referred to as:
- External Storage FM200 Fire Suppression System
- External-Pressure Fire Extinguishing System
- Externally Pressurized HFC-227ea Fire Suppression System
What sets it apart from a conventional stored-pressure FM200 system is a deceptively simple but powerful design choice: storing the FM200 agent and nitrogen driving gas separately. This structural difference improves agent conveyance performance, increases discharge stability, supports significantly longer piping distances, and delivers greater flexibility for large protected areas or projects where the cylinder room sits far from the area it protects.
For data centers, control rooms, archive rooms, libraries, computer rooms, power distribution rooms, and other mission-critical facilities, HazenFire’s externally pressurized FM200 system delivers a genuinely professional total flooding clean agent fire protection solution.
Understanding FM200 / HFC-227ea
FM200, chemically known as Heptafluoropropane (HFC-227ea), is a clean gaseous fire extinguishing agent that suppresses fire through both physical and chemical mechanisms. It offers strong electrical insulation performance, high fire extinguishing efficiency, and zero ozone depletion potential.
The standout advantage: FM200 leaves no residue after discharge. For protected spaces where post-incident cleanup is difficult or where any contamination is simply unacceptable, this property alone often makes the decision.
Typical Assets Protected by FM200
- Data servers
- Control cabinets
- Electrical equipment
- Critical records
- Computer hardware and software
- Precision instruments
- Archives and documents
- Cultural relics and valuable collections
Because FM200 leaves behind no powder, foam, or water residue, it has become a go-to choice for clean agent fire suppression in high-value and sensitive environments worldwide.
What Actually Makes a System “Externally Pressurized”?
In a traditional stored-pressure FM200 system, the agent and nitrogen share the same cylinder — nitrogen pressurizes the cylinder throughout standby and helps drive discharge when the system activates.
HazenFire’s Externally Pressurized FM200 system takes a fundamentally different approach.
Here, the FM200 agent is stored as a liquid inside the agent cylinder without nitrogen pressurization. The pressure inside that cylinder is simply the agent’s own saturated vapor pressure. The compressed nitrogen that eventually drives discharge lives in its own separate, high-pressure cylinder entirely.
When the system activates, high-pressure nitrogen first passes through a pressure-reducing device, then enters the FM200 agent cylinder — pushing the liquid agent through the siphon tube, container valve, piping network, and nozzles into the protected area.
This separation of roles is why the system carries several alternate names:
- External Storage FM200 Fire Suppression System
- External-Pressure Fire Extinguishing System
- Separate Nitrogen Cylinder Fire Suppression System
- Nitrogen-Driven FM200 Fire Suppression System
- Separate Pressure Source Fire Suppression System
The core concept, distilled: FM200 agent and nitrogen driving gas live in separate cylinders. Nitrogen only enters the FM200 cylinder the moment the system is activated — not a second before.
How the System Works: From Detection to Discharge
HazenFire’s externally pressurized FM200 system integrates fire detection, alarm control, distribution and release equipment, agent storage, driving gas storage, piping network, nozzles, and alarm indication devices into one coordinated response chain.
1. Fire detectors sense smoke, heat, or flame → alarm sent to control panel
2. Control panel confirms fire signal → activates audible/visual alarms
sends linkage signals to stop ventilation, close dampers, shut down systems
3. After preset delay time → control panel sends release signal to actuation device
4. Pilot gas cylinder opens selector valve and driving gas cylinder valve
5. Nitrogen driving gas releases and passes through pressure-reducing device
6. Regulated nitrogen enters FM200 agent cylinder → pushes agent through piping
7. FM200 discharges through nozzles into protected area
→ reaches designed extinguishing concentrationThis is a total flooding suppression design — the agent fills the entire protected enclosure to suppress fire quickly and uniformly, leaving no gaps in coverage.
Why Separate Storage Actually Matters
The separated storage architecture isn’t a cosmetic design choice — it solves two genuine engineering problems.
Problem 1: Gas dissolution during standby. When FM200 and nitrogen share a cylinder, the agent remains in contact with pressurizing nitrogen continuously. In HazenFire’s externally pressurized design, the agent never contacts nitrogen during normal storage, eliminating this dissolution risk entirely.
Problem 2: Vapor separation during discharge. After activation, maintaining agent conveyance pressure above storage pressure helps prevent vapor separation and reduces the two-phase flow phenomenon that can destabilize discharge in conventional systems.
The practical result: nitrogen stays behind the liquid FM200 agent, continuously pushing it forward through the piping network with a faster, more stable flow than a stored-pressure system can typically achieve. This directly improves the piping network’s agent conveyance capability — making the system far better suited to long-distance discharge applications.
Externally Pressurized vs. Stored-Pressure FM200: A Direct Comparison
Both systems use the same FM200 / HFC-227ea agent. The difference lies entirely in storage and discharge architecture.
| Feature | Stored-Pressure FM200 | HazenFire Externally Pressurized FM200 |
|---|---|---|
| Storage configuration | Agent + nitrogen in same cylinder | Agent and nitrogen stored separately |
| Standby cylinder pressure | Pressurized continuously | Agent cylinder unpressurized (vapor pressure only) |
| Nitrogen contact with agent | Continuous | Only during discharge |
| Agent flow stability | Standard | Enhanced — more stable, less pressure fluctuation |
| Piping distance capability | Standard | Long-distance capable (up to 200 m) |
| Best suited for | Standard rooms, normal piping runs | Large volumes, long piping, centralized cylinder rooms |
| System complexity | Simpler structure | More advanced engineering design |
For small, standard protected rooms, a stored-pressure FM200 system may well be sufficient. But for large-scale projects, long piping routes, or centralized cylinder room designs, HazenFire’s externally pressurized FM200 system delivers measurably better engineering flexibility.
Six Key Advantages of HazenFire’s External Storage FM200 System
1. Longer Agent Conveyance Distance
Under suitable design conditions, maximum conveyance distance can reach up to 200 meters — a critical advantage when the cylinder room can’t be positioned close to the protected area. This proves especially valuable for large data centers, industrial control rooms, underground equipment rooms, large power distribution facilities, and centralized cylinder room projects serving multiple protected zones.
2. More Stable Discharge Performance
Because nitrogen enters the agent cylinder only at the moment of discharge, the system maintains more consistent driving pressure throughout. The pressure-reducing device regulates nitrogen pressure precisely before it reaches the FM200 cylinder, stabilizing agent flow rate, nozzle inlet pressure, agent atomization, discharge uniformity, and ultimately, fire extinguishing efficiency.
3. Better Nozzle Atomization
By adjusting driving pressure and nitrogen configuration, the externally pressurized design increases nozzle inlet pressure — directly improving FM200 atomization. For total flooding suppression, where the entire protected space must reach required extinguishing concentration uniformly, superior atomization translates directly into better real-world performance.
4. Higher Cylinder Utilization
Since the agent cylinder stores FM200 without nitrogen pressurization during standby, filling density can reach up to 1249 kg/m³ — substantially higher than conventional arrangements. This means fewer cylinders, more efficient use of cylinder room space, and meaningful cost savings on space-constrained projects.
5. Potential for Smaller Piping Diameter
Strong, stable driving pressure allows more agent to be conveyed efficiently through the piping network, which can — under suitable design conditions — permit relatively smaller piping diameter compared to conventional arrangements. The result: reduced piping cost and greater project flexibility.
6. Ideal for Halon 1301 Replacement Projects
For facilities still running legacy Halon 1301 systems, HazenFire’s externally pressurized FM200 system offers a credible retrofit path. In many projects, existing cylinder rooms and piping networks can be reused following proper engineering evaluation — significantly reducing reconstruction work and overall project cost.
Where This System Belongs
HazenFire’s externally pressurized HFC-227ea fire suppression system is built for protected areas demanding fast fire suppression with zero tolerance for residue.
Typical Applications
- Data centers and server rooms
- Computer rooms and control rooms
- Power distribution and electrical rooms
- Telecommunication rooms
- Archive rooms and libraries
- Museums and cultural relic storage rooms
- Precision medical equipment rooms
- Precision industrial instrument rooms
- Critical record storage rooms
- High-value asset rooms
- Large-volume protected areas
- Projects with long-distance piping requirements
- Facilities where the cylinder room sits far from the protected zone
It’s especially well-suited to spaces holding valuable assets, critical records, electronic equipment, or essential hardware and software systems.
What Fires Can FM200 Actually Suppress?
FM200 fire suppression is effective against:
- Electrical fires
- Surface fires involving solid materials
- Liquid fires
- Gas fires where the gas supply can be shut off before discharge
Important limitation: FM200 is not suitable for fires involving oxidizing chemicals, reactive metals, metal hydrides, or self-decomposing chemicals such as hydrogen peroxide or hydrazine.
This is precisely why proper system design and a thorough fire risk evaluation must precede any FM200 system selection — clean agent suppression is powerful, but it isn’t universal.
Technical Specifications
| Specification | Detail |
|---|---|
| Extinguishing agent | FM200 / HFC-227ea |
| Extinguishing method | Total flooding |
| Rated working pressure at 20°C | 4.2 MPa |
| Agent discharge time | ≤ 10 seconds |
| Agent cylinder volume | 90 L, 120 L, 150 L, 180 L |
| Maximum filling density | ≤ 1250 kg/m³ |
| Driving gas | Nitrogen |
| Driving gas cylinder volume | 70 L |
| Driving gas storage pressure | 12 MPa |
| Pilot cylinder volume | 5 L |
| Pilot cylinder storage pressure | 6 MPa |
| Main power supply | AC 220 V, 50 Hz |
| Backup power supply | DC 24 V |
| Solenoid actuation voltage | DC 24 V |
| Automatic delay time | 0–30 seconds, adjustable |
The system supports automatic control, electrical manual control, and mechanical emergency manual control — giving operators multiple layers of activation reliability.
When Should You Choose an Externally Pressurized FM200 System?
This system architecture earns its place when:
- The cylinder room is positioned far from the protected area
- The project involves long piping distance
- The protected area is large in volume
- Stable discharge pressure is a project requirement
- Total flooding clean agent protection is needed
- Post-discharge cleaning must be minimized or eliminated
- The protected area houses high-value electronic equipment or critical documents
- The project involves Halon 1301 replacement or system retrofit
Engineering Flexibility for Complex Fire Protection Challenges
An externally pressurized FM200 fire suppression system isn’t simply another clean agent option on the shelf — it’s a purpose-engineered solution for projects demanding stronger agent conveyance capability and genuine design flexibility.
For engineering contractors, system integrators, and project owners navigating complex clean agent fire protection requirements, HazenFire’s external storage FM200 system delivers the performance, stability, and flexibility that conventional stored-pressure systems simply weren’t designed to provide.
Clean suppression. Stable discharge. Engineered for the projects where it matters most.
HazenFire — Clean Agent Fire Suppression. Engineered for Critical Infrastructure.
