Gas Fire Extinguishing System Overpressure Risks and Preventive Measures
1. Core Causes of Cylinder Overpressure Risks
Gas cylinders for fire suppression systems bear continuous internal pressure during long-term service. Their pressure resistance and structural stability can be weakened by external environmental pollution, internal medium corrosion, and long-term fatigue load. Once the cylinder performance fails to meet operational pressure requirements, overpressure failure or accidental explosion will easily happen, resulting in system failure and safety accidents.
2. Strict Cylinder Inspection and Scrapping Standards
Regular professional inspection and timely scrapping of expired cylinders are the core measures to avoid overpressure risks. All fire-fighting gas cylinders must be inspected periodically in accordance with unified industry specifications and retired immediately when reaching the service life.
In China, cylinder management complies with the Safety Technical Code for Gas Cylinders (TSG 23-2021), which strictly standardizes cylinder permanent steel marks, scrapping cycles, periodic inspection intervals, and qualification verification. For international projects, relevant ISO and NFPA industry standards shall be followed to ensure consistent safety compliance.
3. Standardized Handling, Storage and Usage Specifications
The full lifecycle management of fire-fighting cylinders (handling, stacking, storage, and on-site operation) must follow standardized safety guidelines. The Safety Regulations for the Handling, Handling, Storage and Use of Gas Cylinders (GB/T34525-2017) provides systematic operational specifications for domestic applications. For global projects, local safety codes and international pressure vessel management standards shall prevail to avoid safety hazards caused by irregular manual operation.
4. Standardized Charging Pressure for Prefabricated Fire Suppression Systems
To avoid system overpressure during standby and startup, the charging pressure of prefabricated gas fire extinguishing systems installed in protected zones shall not exceed 2.5 MPa. Excessive charging pressure will increase the long-term load of cylinder storage devices and pipeline components, greatly raising the probability of overpressure failure in high-temperature environments or long-term standby conditions.
5. Special Storage Requirements for High-Pressure Mixed Gas Systems
IG541 mixed gas and other inert gas fire extinguishing systems are kept in a continuous high-pressure storage state. Compared with conventional fire suppression systems, they have stricter safety thresholds for storage and pressure relief.
In addition to meeting the basic ventilation and fireproof requirements of ordinary storage rooms, high-pressure gas storage devices must fully comply with international high-pressure container storage regulations and be equipped with qualified pressure relief and ventilation facilities to eliminate cumulative overpressure risks caused by ambient temperature changes and long-term storage.
6. Standard Operating Rules for Combined Distribution Systems
For combined pipe network fire extinguishing systems, the sequence of valve opening directly affects system pressure balance. During system startup, the selector valve must be opened before or synchronously with the container valve. Non-standard operation will cause instantaneous pressure surge in local pipelines, trigger system overpressure alarms, and even damage pipeline accessories and pressure gauges.
7. Professional Layout and Environmental Requirements for Storage Devices
All storage devices of pipe network and prefabricated gas fire extinguishing systems must be placed in independent professional storage rooms to ensure centralized safety management.
Key layout and environmental requirements are as follows:
Building grade: The fire resistance rating of the storage room shall be no lower than Grade II, complying with pressure vessel storage and building fire protection specifications.
Site access: The storage room shall be equipped with direct outdoor exits or evacuation passages to facilitate emergency disposal.
Ambient temperature: The applicable temperature range for conventional gas fire suppression system storage rooms and protected zones is -10°C to 50°C (14°F to 122°F). For high-pressure CO₂ fire extinguishing systems, the ambient temperature must be controlled within 0°C to 49°C (32°F to 120°F) to prevent temperature-induced pressure fluctuation and overpressure risks.
Operation space: Storage devices shall be arranged away from direct sunlight to avoid thermal radiation pressure rise. The operation clearance between equipment and walls or between double-row equipment shall not be less than 1.0 meter, and no less than 1.5 times the outer diameter of the storage container, ensuring convenient daily operation and maintenance.
8. Summary of Overpressure Prevention Best Practices
System overpressure risks mainly come from unqualified cylinder performance, non-standard charging pressure, irregular storage environment, and incorrect operation procedures. Strict implementation of periodic inspection and scrapping systems, standardized pressure control, compliant storage layout, and standardized startup operation can effectively eliminate overpressure hazards and ensure long-term stable and safe operation of gas fire extinguishing systems.
