Product Overview of the Internally Pressurized Pipeline Network Heptafluoropropane Fire Suppression System, 4.2 MPa

1.1 System Overview

The piped‑network heptafluoropropane fire suppression system comprises a cylinder rack, extinguishing agent cylinders, container valves, high‑pressure hoses, liquid check valves, manifolds, safety relief devices, selection valves, signal feedback units, extinguishing agent delivery pipelines, nozzles, pilot cylinders, actuators, initiating pipelines, and initiating gas check valves, making it an intelligent automatic fire suppression system. Depending on the specific application requirements, it can be configured as either a unitary independent system or a combined distribution system, employing total flooding to provide fire protection for both single and multiple protected zones. The system features advanced technology, high extinguishing efficiency, and convenient maintenance. It offers three activation modes: automatic, manual, and mechanical emergency operation.

1.2 Application Areas

This system is primarily applicable to the following types of fires:

1. Solid surface fires;
2. Liquid fires;
3. Gas fires in which the gas supply can be shut off before extinguishing;
4. Electrical fire;

Typical citation locations:

It is primarily intended for fire protection in critical facilities such as computer rooms, data processing centers, telecommunications facilities, process control centers, high‑value medical equipment, precision industrial equipment, museums and art galleries, libraries, archives, vaults for valuable items, emergency power installations, flammable liquid storage areas, and cleanrooms. It can also be used in production environments with fire hazards, including paint‑spraying lines, electrical appliance aging rooms, rolling mills, printing presses, melting tanks, drying equipment, coal‑powder silos in cement production processes, as well as ship engine rooms and cargo holds.

1.3 Fire-extinguishing agent

This system uses heptafluoropropane ( HFC-227 ea ) as a fire suppressant. Heptafluoropropane primarily relies on chemical suppression while also providing physical extinguishing effects; it is colorless, odorless, clean, non-conductive, and does not contaminate the protected object. It causes no damage to property or precision equipment and has no adverse impact on the atmospheric ozone layer ( ODP The value is zero, meeting environmental protection requirements; in most protected areas, the extinguishing concentration is below the threshold for non‑toxic effects on humans. NOAEL Its concentration is safe for humans, making it an excellent clean‑gas fire suppressant.

1.4 Safety Warning

1 ) When heptafluoropropane is discharged, it generates a condensing vapor mist that extinguishes fires by interrupting the combustion chain, achieving rapid fire suppression. If used in occupied spaces, the system must be equipped with a delay to allow personnel to evacuate within that time period.

2 ) User units shall install conspicuous warning signs at the following locations; recommended wording for the signs is as follows:

    a ) Warning sign within the protected area: Warning! Upon hearing the on-site alarm, personnel must evacuate immediately.

    b ) At the emergency start button location: Warning! When initiating a mechanical emergency start, ensure that no one is present within the protected area.

3 ) In addition to the aforementioned warnings, other safety measures shall comply with the relevant current national regulations.

2. Fire Suppression System Control Program

3. Fire Suppression System Schematic Diagram

3.1 Unit-Independent System

A unit‑independent system refers to a fire suppression system that employs a single extinguishing agent storage unit to protect a single protected zone, and is used in facilities with special requirements or in standalone protected zones.

When a fire occurs in the protected area, the fire alarm and suppression control panel issues a command to open the initiating cylinder, releasing the initiating gas. The initiating gas travels through the initiating pipeline, opening the container valve of the extinguishing agent cylinder assembly and releasing the extinguishing agent. The extinguishing agent is then discharged into the protected area via a high-pressure hose, a liquid‑side check valve, a manifold, the extinguishing agent delivery piping, and nozzles, thereby achieving fire suppression.

The architecture of the unit‑independent system is shown in the figure:

1. Fire-extinguishing agent cylinder rack 2. Initiating cylinder 3. Pressure gauge for the initiating cylinder 4. Container valve of the initiating cylinder

5. Electromagnetic actuator shear pin 6. Electromagnetic actuator 7. Mechanical emergency‑start shear pin

8. Mechanical emergency start button 9. Low-leakage, high-seal valve 10. Fire-extinguishing agent delivery pipeline 11. Nozzle

12. Fire alarm and fire suppression control panel 13. Signal feedback device 14. Safety relief device 15. Manifold

16. Liquid check valve 17. High-pressure hose 18. Mechanical emergency start handle

19. Pneumatic actuator 20. Container valve for the extinguishing agent cylinder assembly 21. Pressure gauge for the extinguishing agent cylinder assembly

22. Starting Piping 23. Extinguishing Agent Cylinder Assembly 24. Cylinder Assembly Clamp

3.2 Combined Distribution System

A combined distribution system refers to a fire‑extinguishing agent storage unit that, via a network of piping and selective distribution, protects two or more protected zones. With the exception of its combined distribution control—employing a combination of a pilot‑gas check valve and a selection valve—the system is otherwise identical to a unit‑independent system.

The combined distribution system is suitable for protecting two or more protected zones. Its key feature is that each zone is equipped with its own initiating cylinder and selection valve, while the extinguishing agent storage cylinders are shared—calculated based on the largest protected zone—enabling multi-zone combined protection and reducing initial capital investment.

When a fire occurs in any protected zone, the fire alarm and suppression control panel issues a command to open the initiating cylinder associated with that zone, releasing initiating gas. The initiating gas travels through the initiating pipeline to open the selection valve for the zone and the corresponding container valve of the extinguishing agent cylinder assembly. The extinguishing agent is then discharged into the protected zone via a high-pressure hose, a liquid‑side check valve, a manifold, connecting pipes, a distribution manifold, the opened selection valve, and the extinguishing agent delivery piping. The initiating gas opens only the selection valve for the designated zone, ensuring that the extinguishing agent does not enter other zones; meanwhile, the one‑way check valve on the initiating gas line restricts flow to the specific extinguishing agent cylinder assembly associated with that zone.

The structure of the combined distribution system is shown in the figure:

1. Cylinder rack for initiating cylinders 2. Initiating cylinder 3. Cylinder clamp for initiating cylinders 4. Pressure gauge for initiating cylinders

5. Pilot bottle container valve 6. Low-leakage, high-seal valve 7. Safety pin for electromagnetic actuator

8. Electromagnetic actuator for the initiating cylinder 9. Mechanical emergency‑start safety pin 10. Mechanical emergency‑start button 11. Distribution manifold 12. Zone A selection valve 13. Zone A fire‑extinguishing delivery pipeline

14. Signal feedback device for Zones A and B 15. Fire‑extinguishing delivery piping for Zone B 16. Selection valve for Zone B 17. Connecting pipe 18. Start‑up gas check valve 19. Start‑up pipeline 20. Safety relief device 21. Nozzle 22. Manifold 23. Liquid check valve 24. High‑pressure hose–fire‑extinguishing agent cylinder rack

25. Mechanical Emergency Start Handle 26. Pneumatic Actuator 27. Extinguishing Agent Cylinder Container Valve

28. Fire-extinguishing agent cylinder pressure gauge 29. Fire-extinguishing agent cylinder rack 30. Fire-extinguishing agent cylinder

31. Cylinder bundle clamp

4. Startup Method

This system offers three startup modes: automatic startup, manual startup, and mechanical emergency‑operation startup.

4.1 Automatic Startup Mode

Gas fire‑extinguishing alarm and control systems are typically equipped with two different types of fire detectors. The control panel features an “automatic/manual” switching function (which may also be provided as a separate switch located outside the protected area). When set to the “automatic” position, the fire‑extinguishing system operates in automatic mode.

When only one detector sends a fire signal, the control panel activates the alarm bell and the audible‑visual alarm to alert personnel of a fire, but it does not initiate the fire suppression system.

When both detectors issue fire signals, the control panel activates the alarm bell or the audible‑visual alarm, interlocks to close all openings in the protected zone, and initiates a fire‑extinguishing start‑up delay. Once the preset delay period elapses, the fire‑extinguishing system automatically starts.

If, during the spray‑delay period, it is determined that activation of the fire‑extinguishing system is not required, the “Emergency Stop” button located outside the protected zone or on the controller may be pressed to terminate the extinguishing command.

4.2 Manual Start Mode

When the transfer switch is set to the “Manual” position, the fire suppression system operates in manual mode.

In this mode, the detector sends a fire signal, prompting the control panel to activate the alarm bells and the audible‑visual alarms to alert personnel of the fire, but without initiating the fire suppression system. At this point, pressing the “Manual Start” or “Emergency Start” button on the external control panel or on the controller will trigger the fire suppression system.

Note: Regardless of whether the control host is in automatic or manual mode, pressing either the “Emergency Start” or “Manual Start” button will activate the fire suppression system.

4.3 Mechanical Emergency Operation Initiation Method

When both automatic and manual activation fail, perform the mechanical emergency operation according to the following steps: 1) Manually shut down the linked equipment and disconnect the power supply; 2) Remove the “mechanical emergency start safety pin” from the solenoid‑actuated actuator of the corresponding protected zone’s initiating cylinder, then press the mechanical emergency start button. The solenoid‑actuated actuator will open the initiating cylinder, releasing the initiating gas to activate the fire suppression system.  

5. Main Technical Parameters

The main technical parameters of the piped‑network heptafluoropropane fire suppression system are shown in the table below.

FAQ for 4.2 MPa Stored‑Pressure Halon‑Free Fire Suppression Systems

Q: What types of facilities are suitable for an internally pressurized 4.2 MPa heptafluoropropane fire suppression system?

A: Suitable for small and medium-sized protected areas such as computer rooms, distribution rooms, archives, and energy storage compartments; capable of extinguishing Class A, B, and C fires, as well as energized electrical fires.

Q: What is the core difference between internally pressurized and externally pressurized heptafluoropropane systems?

A: In an internally pressurized system, the extinguishing agent and the driving nitrogen are stored together in the same cylinder; in an externally pressurized system, the extinguishing agent and the driving gas are stored in separate cylinders. The internally pressurized system has a simpler structure and shorter piping.

Q: What startup methods does the system support?

A: It features three activation modes—automatic, manual, and mechanical emergency—and can be connected to a fire alarm control panel, enabling interlocked activation of the discharge system via smoke and heat detectors.

Q: What does 4.2 MPa mean?

A: Refers to the rated storage pressure of the extinguishing agent in the cylinder, which is 4.2 MPa at the specified temperature; this is the design storage pressure parameter for this system model.

Q: What are the key considerations for system installation and construction?

A: The cylinder assembly is installed in a dedicated cylinder room, with nozzles arranged appropriately and piping subjected to pressure testing in accordance with relevant standards to ensure tight sealing and uniform discharge of the extinguishing agent into the protected area.

Q: What items should be inspected during routine maintenance?

A: Regularly inspect the cylinder pressure gauge, cylinder valve, and pipeline connections for leaks; check the fire alarm interlock devices; and examine the cylinder body for rust or deformation.

Q: What are the effects of a heptafluoropropane discharge on personnel within the protected area?

A: Prior to discharge, an audible and visual alarm will be activated, and personnel must evacuate promptly. Entry into the protected area is prohibited during the discharge process; entry may only be permitted after adequate ventilation.

Q: Will the discharged agent damage precision electronic equipment?

A: Heptafluoropropane is a clean agent that leaves no particulate residue and exhibits extremely low corrosivity, making it compatible with precision electrical equipment in server rooms; after extinguishing, simply ventilate the area.

Q: Can the agent be refilled on-site after it has been released?

A: On-site refilling is not permitted. After discharge, the cylinders must be transported back to a qualified fire‑safety organization for inspection and recharging with the extinguishing agent and propellant gas.

Q: Does this system meet the acceptance requirements for fire protection projects?

A: The product is accompanied by a fire‑safety inspection report and complies with relevant gas‑extinguishing standards. Upon completion of installation and commissioning, it can be integrated with the protected area to facilitate overall fire‑safety acceptance.