Product Overview of Temperature-Activated Automatic Gas Fire Suppression Systems

I. Overview

The temperature‑sensing self‑activating fire suppression device (hereinafter referred to as the temperature‑sensing self‑activating fire suppression device) is an innovative invention in the fire protection industry. As a simple, low‑cost, and highly reliable standalone automatic fire suppression system, it requires no external power supply, no dedicated smoke or heat detectors, and no complex equipment or piping. Relying on its own stored pressure, it uses a pressurized fire detection tube and a set of fire detection cylinders to quickly, accurately, and effectively detect and extinguish the source of a fire, integrating alarm and extinguishing functions to put out fires at their very earliest stage. This approach not only significantly reduces installation costs but also lowers the cost per fire‑suppression event, while ensuring no harm to personnel. By adopting this temperature‑sensing self‑activating fire suppression device, protection can be shifted from safeguarding large enclosed spaces to directly protecting valuable equipment housed in various smaller enclosed areas.

II. Technical Specifications

1. Operating principle of the temperature-sensitive self‑initiating fire suppression system

A heat‑activated automatic fire‑extinguishing system consists of a pressurized vessel containing the extinguishing agent, a container valve, and fire‑detecting tubes and/or discharge pipes that release the extinguishing agent. The fire‑detecting tube is installed near or directly above the area where a fire is most likely to originate, with detection carried out via multiple sensing points (linear detection) along its length. When a fire occurs, the tube softens and ruptures at the point of highest temperature, releasing the extinguishing medium into the protected area either through the tube itself (in a direct‑action system) or via nozzles (in an indirect‑action system). Its… Among them, the fire‑detecting tube is a newly developed product in the high‑tech field, a cutting‑edge non‑metallic composite. It combines long‑term leak resistance, flexibility, and reliable temperature sensitivity; within a specified temperature range, it bursts to discharge an extinguishing agent or transmit a fire‑alarm signal.

2. Features of the Temperature-Activated Automatic Fire Suppression System

● Combines alarm and fire suppression in one, with rapid detection and response, swiftly extinguishing fires at their earliest stage and effectively minimizing economic losses caused by fires.

● This device requires no external power supply and is unaffected by vibration or impact, ensuring reliable operation. It also remains immune to degradation of its fire‑detection performance and false alarms caused by oil, dust, or smoke.

● The fire detection tube is a flexible component that is unaffected by installation orientation, enabling it to be inserted into various narrow, complex, and flammable spaces or equipment. This feature addresses the limitations of existing fire‑suppression products, which are unable to extinguish such fire sources.

● Close proximity to the protected object ensures high firefighting efficiency at low cost.

● Non‑total flooding; during discharge, it will not harm personnel in the protected area.

●Ideal for equipment and facilities that require critical protection while operating unattended.

● Simple design, easy installation, minimal footprint, and no need for a separate cylinder room.

3. Scope of Application

● Microwave equipment rooms, decimeter‑wave equipment rooms, meter‑wave equipment rooms, transformer and distribution rooms, and uninterruptible power supply (UPS) rooms within radio and television transmission towers;

● The program-controlled switchroom, control room, and signaling transfer point room of the communication system;

● Control rooms, electronic equipment rooms, computer rooms, relay rooms, and switchgear and distribution rooms in power plants, as well as areas such as cable crossings, cable bundles, and intermediate joints;

● Power distribution and transformation cabinets, elevator control cabinets, and cable trays or cable ladders with trunking;

● Special or critical cabinet equipment housed in relatively sealed enclosures at other locations.

III. System Architecture

1. Direct-Acting Heat-Sensitive Automatic Fire Suppression System

● The fire‑detecting tube is connected to the extinguishing‑agent container via a container valve to detect the fire source. When exposed to heat, the tube ruptures; the resulting pressure drop in the tube triggers the container valve, which, through a conversion fitting at the valve outlet, directs the extinguishing agent to be discharged through the original rupture point of the fire‑detecting tube.

Direct‑type heat‑sensitive self‑activating fire extinguishing devices can be classified according to the type of stored extinguishing agent as follows:

Carbon Dioxide Direct-Acting Heat-Sensitive Self-Starting Fire Extinguishing Device

Heptafluoropropane temperature‑sensitive self‑activating fire suppression system

Perfluorohexanone temperature‑sensitive self‑activating fire suppression system

2. Indirect-Acting Heat-Sensitive Automatic Fire Suppression System

● The fire detection tube is connected to the extinguishing agent container via a container valve to detect the fire source. When exposed to fire, the tube ruptures; the resulting pressure drop activates the container valve, which releases the extinguishing agent through the discharge line to the nozzle.

Indirect‑type fire‑sensing, temperature‑activated automatic fire‑extinguishing device, according to the stored extinguishing agent.

Depending on the type, they can be classified as:

Carbon Dioxide Indirect-Acting Temperature-Sensitive Automatic Fire Extinguishing System

Heptafluoropropane Indirect-Acting Heat-Activated Automatic Fire Suppression System

Perfluorohexanone Indirect‑Type Heat‑Activated Self‑Starting Fire Suppression System

IV. System Design

1. The heptafluoropropane temperature‑sensitive automatic fire suppression system can be used to extinguish the following types of fires:

● Flammable gas fire.

● Class A, B, and C liquid fires.

● Surface fires on solids.

● Electrical fires.

2. Carbon dioxide and heptafluoropropane heat‑sensitive automatic fire‑extinguishing systems shall not be used to extinguish the following types of fires:

● Fires involving oxidizer‑containing chemical products such as nitrocellulose and gunpowder;

● Fires involving reactive metals such as potassium, sodium, magnesium, titanium, and zirconium;

● Fires involving metal hydrides such as potassium hydride and sodium hydride.

3. The heat‑sensitive self‑activating fire suppression system designates relatively enclosed, small‑volume equipment within either compact spaces or larger areas as the protected zone.

When a direct‑type fire detection and extinguishing system is used, the volume of the protected area shall not exceed 10 m³. ³ ; When an indirect-type fire detection and extinguishing system is used, the volume of the protected area shall not exceed 100 m³. ³。

4. For areas protected by temperature‑sensing, self‑activating fire suppression systems, if the premises are finished with flame‑retardant or non‑combustible materials, use flame‑retardant wires and cables, and implement firestop measures in accordance with applicable codes, no additional automatic fire suppression systems are required.

5. Design Parameters: The design quantity of the extinguishing agent for temperature‑sensitive, self‑activating fire suppression systems shall be determined based on the fire characteristics of the protected object and the volume of the protected zone. The design parameters shall comply with the provisions in Table 1, and the carbon dioxide and heptafluoropropane extinguishing agents shall respectively meet the requirements of GB 4066‑1994 and GB 15060‑1994.

Table 1: Technical Parameters of Temperature-Activated Automatic Fire Suppression Systems

Table 2: Main Technical Parameters of Fire Detection Tubes

Table 3: Specifications and Models of Heat-Activated Automatic Fire Extinguishing Devices

6. The release piping used in indirect‑type heat‑sensitive automatic fire‑extinguishing systems shall comply with the following requirements:

A. Carbon Dioxide Release Pipe

Material: The release tube shall be made of seamless copper alloy tubing with an outer diameter of Φ14 mm.

Working pressure: shall not be less than 10 MPa.

B. Heptafluoropropane (Perfluorohexanone) Release Pipe

Material: Soft fire‑detecting tubing with an outer diameter of Φ6 mm, subjected to high‑temperature annealing.

Working pressure: shall not be less than 1.8 MPa.

7. Carbon dioxide fire extinguishing agents and heptafluoropropane fire extinguishing agents shall each comply with the provisions of the current national standards GB 4066 and GB 18614, respectively.

The fire detection tube shall be installed no more than 1 meter from the protected area; see the figure below for installation requirements.

The effective protection zones of each nozzle are shown in the figure below:

V. Installation and Commissioning

1. The installation of temperature‑sensitive automatic fire‑extinguishing systems shall be carried out by personnel and teams who have undergone specialized training.

2. Prior to the installation of temperature‑sensitive automatic fire‑extinguishing systems, the following technical documents shall be available:

● Construction drawings, design documents, and relevant technical documents;

● Inspection reports certifying compliance with mandatory or type‑approval requirements issued by a nationally designated inspection body;

● Certificate of product conformity and instructions for use and maintenance;

● The design unit shall provide the construction unit with a detailed description of the project and relevant precautions.

3. Commissioning of the heat‑activated automatic fire suppression system: After installing the heat‑activated automatic fire suppression device, remove the terminal pressure gauge from the check valve assembly, then connect the dedicated inflation fitting to the check valve assembly. Use this fitting to pressurize the fire detection tube to 10 bar (1.0 MPa) with nitrogen (with the ball valve in the closed position).

● Make a mark at the position indicated by the pressure gauge pointer.

● Inspect the fire detection tube for leaks; the typical inspection period is 10 minutes per meter of fire detection tube.

● While observing the fire detection tube, also inspect the device for any abnormalities.

● If, during the installation of a heat‑activated automatic fire‑extinguishing device, the protected space or area has not yet been completed, it is advisable to wait until the project is finished before opening the ball valve of the device, thereby preventing unintended activation.

● If the extinguishing agent container valve of the system is equipped with a pressure switch, the pressure switch only measures the pressure inside the container when the ball valve is closed; therefore, the electrical circuit can be installed at this time. Once the ball valve is opened, the pressure switch will monitor the pressure in the fire detection tube.

● When commissioning indirect‑type systems, it is recommended to slightly restrict the outlet of the extinguishing‑agent container valve to prevent unintended discharge. However, do not fully close the valve outlet to avoid pressure buildup. If pressure builds up, the extinguishing agent may be discharged when the restriction is removed at the end of commissioning.

● Once it has been confirmed that the installation of the heat‑activated automatic fire‑extinguishing device is fully compliant and that there are no pressure leaks in the fire detection tube, the ball valve may be opened gradually (by turning it 45° counterclockwise). The ball valve should be opened slowly to allow the pressure in the fire detection tube and within the container to equalize progressively.

VI. Maintenance and Care

1. Temperature‑sensing automatic fire‑extinguishing systems shall be subject to regular maintenance and management. Maintenance personnel shall be familiar with the system’s operating principles and performance, and all maintenance activities shall be documented.

2. The pressure indications of the fire‑extinguishing agent storage container and the fire‑detection tube pressure gauge of the heat‑activated automatic fire‑extinguishing system shall be checked weekly, and any pressure drop shall not exceed 10% of the operating pressure.

3. The equipment components shall be inspected quarterly and shall meet the following requirements:

● The fire-extinguishing agent storage container shall be free of mechanical damage, with a rust-free surface and intact coating protection; its nameplate and markings shall be clear.

● The release tube shall be securely fastened and free from looseness;

● The nozzle shall be free of deformation and damage, and its orifice shall be clean and unobstructed.

4. Each year, the heat‑activated automatic fire‑extinguishing system shall undergo a comprehensive inspection and maintenance; in addition to meeting the requirements of items 2 and 3, it shall also comply with the following provisions:

● Fire-extinguishing agent storage containers shall be securely fastened and free from looseness;

● Carbon dioxide temperature‑sensitive self‑activating fire suppression systems shall use the gravimetric method; heptafluoropropane and perfluorohexanone temperature‑sensitive self‑activating fire suppression systems shall measure the stored extinguishing agent quantity by means of a pressure gauge, and the measured value shall not be less than 10% of the originally charged amount.

● The fire detection tube shall be free from deformation, corrosion, damage, and aging.

5. In the event of a system malfunction, it is strictly prohibited to disassemble or modify any component of the system without first notifying qualified installation personnel.

6. Perform regular inspections, and if the pointer on the device’s terminal pressure gauge is outside the green zone, promptly notify qualified installation personnel.

7. When the system discharges the extinguishing agent, white frost may appear on the cylinder or other metal components. This is caused by the rapid discharge rate, which creates a significant temperature difference between the cylinder and the ambient environment; this is a normal phenomenon. The condition will return to normal once the discharge is complete.

VII. System Faults and Troubleshooting

Note: All troubleshooting must be performed by our trained, qualified personnel. If the above troubleshooting procedures prove ineffective, please contact us promptly so that we can address the issue without delay and ensure the system remains in proper working condition at all times.

FAQ on Temperature‑Sensing Automatic Gas Fire Suppression Systems

Q: What types of facilities are suitable for temperature‑sensing, self‑activating gas fire suppression systems?

A: Suitable for enclosed, confined spaces such as distribution cabinets, packaged substations, small server rooms, and energy storage cabins; capable of extinguishing Class A, B, and C fires, as well as energized electrical fires.

Q: What is the operating principle of a heat‑activated, self‑starting gas fire suppression system?

A: It relies on a temperature-sensing element to detect the ambient temperature; when the set temperature is reached, it automatically activates, releasing clean extinguishing gas to rapidly suppress and extinguish fires within the protected area.

Q: What startup methods are available for the device?

A: Standard configuration includes temperature-sensing automatic activation; it can also be integrated with a fire alarm system to enable electrically controlled, interlocked start-up, providing dual-trigger redundancy for enhanced safety.

Q: What precautions should be taken during installation?  

A: Installed inside the protected space, with the nozzle oriented toward the equipment to be protected, ensuring an unobstructed spray path and secure mounting to prevent external impacts from damaging the temperature-sensing components.

Q: What items should be checked during routine inspections?

A: Inspect the device housing for any damage or corrosion, ensure that the temperature-sensing components are intact and undamaged, check that the piping and fittings are securely fastened, and verify the pressure gauge reading against the specified pressure.

Q: Is the fire-extinguishing gas released by this device harmful to humans?

A: During discharge, the oxygen concentration in the protected area drops rapidly; no personnel shall remain inside. Entry to the site is permitted only after ventilation has extinguished the fire.

Q: Will the discharged gas damage precision electrical equipment?

A: Gas-based fire suppressants leave no particulate residue and exhibit extremely low corrosivity, making them far more compatible with switchgear cabinets and precision electronic equipment than dry powders.

Q: Can the device be reused after it has been discharged?

A: Once the discharge is triggered and the agent has been fully released, on-site refilling for reuse is not possible; the entire unit must be replaced with a new one, and the old equipment shall be collected by a qualified entity.

Q: Can the device operate reliably under high- and low-temperature conditions?

A: The product can operate reliably within the equipment’s standard operating temperature range. In extreme high- or low-temperature environments, please verify that the product’s specified operating temperature range is suitable before selecting it.

Q: Does this device meet the fire safety acceptance requirements?

A: The product is accompanied by a fire‑safety inspection report, complies with applicable standards, and, upon installation, can be integrated into the overall fire‑safety acceptance process for the protected area.