Scope and Application
IS 909:1992 applies to all types of fire hoses used in firefighting operations across industrial, commercial, institutional, and residential settings. The standard covers both suction and delivery hoses, though the primary focus is on hoses for delivering water or other approved fire suppression agents at high pressures.
Hose Construction and Materials
- Outer Covering:
The outer layer is designed to provide resistance against abrasion, weather, heat, and chemical exposure. Typically made from synthetic materials such as neoprene or nitrile rubber, or treated natural fibers, the cover protects the hose from physical damage during use. - Inner Lining:
The inner lining must be impermeable and resistant to the transported medium (usually water). It is typically manufactured from rubber or other elastomers that prevent water leakage and maintain flexibility. - Reinforcement Layer:
To withstand high internal pressures, hoses include reinforcement layers made from textile fibers (polyester or nylon) or metal wire braiding. This reinforcement provides tensile strength and resists bursting under pressure.
Dimensions and Sizes
IS 909 defines various nominal hose diameters—commonly 25 mm (1 inch), 38 mm (1.5 inch), 50 mm (2 inch), and 65 mm (2.5 inch)—to suit different firefighting requirements. Hose length is standardized, with typical segments of 15 meters, allowing modular assembly as per the site’s needs.
Performance Criteria
- Pressure Ratings:
Fire hoses must withstand a minimum working pressure of 12 bar (approx. 175 psi) and pass hydrostatic testing at 24 bar to ensure structural integrity. - Flexibility:
Despite reinforcement, hoses must remain flexible for ease of deployment and manoeuvring around obstacles during firefighting. - Burst Pressure:
The standard mandates a burst pressure at least three times the working pressure, ensuring a high safety margin under dynamic firefighting conditions. - Temperature Resistance:
Hoses must retain their physical and functional properties over a temperature range typically from -20°C to +65°C, accommodating diverse climatic conditions. - Resistance to Chemicals and Flames:
Fire hoses should resist degradation when exposed to common firefighting chemicals, oils, and flames.
Testing Procedures
- Hydrostatic Testing:
Each hose is subjected to water pressure at 24 bar to detect leaks, weak spots, or structural failure. - Flexibility Testing:
Repeated bending and twisting tests confirm that hoses maintain integrity without cracking or delamination. - Abrasion and Impact Tests:
The outer cover is tested for resistance to physical damage typical in operational environments.
Coupling Compatibility
Fire hoses manufactured per IS 909 must be compatible with couplings conforming to IS 12232 to ensure quick, secure connections without leakage. This interoperability is crucial for rapid hose assembly and deployment in firefighting.
Maintenance and Storage
Proper maintenance, including drying, cleaning, and regular inspection for damage, is essential to prolong hose life and ensure performance. IS 909 recommends storing hoses in cool, dry places away from direct sunlight and chemicals to prevent premature deterioration.
Conclusion
IS 909:1992 provides comprehensive technical guidelines for fire hoses, emphasizing strength, flexibility, and durability. Compliance with this standard ensures fire hoses reliably deliver high-pressure water to combat fires effectively, forming an indispensable link in fire protection systems.
