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Scope and Application
IS 15397:2003 applies to fixed gaseous fire suppression installations using clean agents (such as FM-200, Novec 1230), inert gases (e.g., nitrogen, argon, IG-541), and carbon dioxide systems. These systems are widely used in data centers, telecommunication facilities, museums, archives, and electrical switchgear rooms where rapid extinguishment with minimal residue is essential.
The standard covers:
- System layout and components.
- Installation procedures.
- Activation and discharge criteria.
- Safety measures and interlocks.
- Inspection and maintenance protocols.
System Components and Design Essentials
- Agent Storage and Supply:
Cylinders or tanks must comply with pressure and material specifications. Storage location, seismic anchoring, and safety clearances are mandated to mitigate risks during discharge or cylinder rupture. - Piping and Discharge Nozzles:
Network piping must withstand system operating pressures, minimize pressure drops, and ensure uniform agent distribution. Nozzle selection is based on agent type and room geometry to achieve design concentration efficiently. - Detection and Control Panels:
Integrated with fire detection (commonly IS 2189 compliant), control panels must provide automatic and manual system activation, system monitoring, and fail-safe shutdown capabilities. - Manual Release Stations and Abort Controls:
These provide authorized personnel with the ability to activate or abort the system as required, improving operational safety and flexibility.
Design Criteria and Calculations
- Agent Concentration and Volume:
The minimum extinguishing concentration is calculated based on standardized test methods to ensure immediate fire suppression without endangering occupants. - Discharge Time:
Rapid agent discharge is critical; IS 15397 requires complete agent release within 10 seconds or less, maintaining the design concentration for the hold time, typically 10 minutes. - Room Integrity:
The protected enclosure must have adequate tightness to retain the agent concentration for the required duration. Leakage rates are assessed, and sealing measures implemented. - Safety Factors:
Considerations include oxygen depletion limits for occupied areas, permissible exposure limits to agents, and ventilation interlocks to prevent re-ignition.
Installation Requirements
- Cylinder Installation:
Cylinders must be securely mounted with accessible pressure gauges and clearly labelled agent type and quantity. - Piping and Nozzle Positioning:
Must avoid obstructions and ensure effective agent dispersion, adhering to manufacturer and IS guidelines. - Detection and Alarm Integration:
Fire detectors trigger pre-discharge alarms with delay features to allow evacuation. Audible and visual alarms must meet intensity and placement requirements. - Emergency Ventilation Controls:
Systems must interface with ventilation to isolate airflows during agent discharge, preventing dilution.
Testing, Commissioning, and Maintenance
- Hydrostatic and Pressure Tests:
Conducted on cylinders and piping to verify structural integrity. - Functional Tests:
Including detector activation, control panel response, manual release operations, and agent discharge simulations. - Leakage Tests:
To confirm room integrity, critical for agent retention. - Periodic Maintenance:
Routine inspection of agent quantity, cylinder condition, detector calibration, and system electronics as prescribed.
Safety and Regulatory Compliance
IS 15397:2003 emphasizes operator safety by requiring:
- Warning signage for hazardous areas.
- Delays and abort options before discharge.
- Compliance with exposure guidelines from agencies such as OSHA and NFPA.
Installation in line with IS 15397 ensures conformity with India’s National Building Code and fire safety legislation, facilitating certification and insurance compliance.
