Quick Closing Valves: Location and Operation in Fire Scenarios
(a) Where They Are Fitted:
Quick closing valves are strategically placed on the outlet lines of tanks containing flammable or hazardous liquids, typically in:
- Fuel oil tanks within engine rooms, boiler rooms, or near emergency generators.
- Tanks storing other flammable liquids in industrial settings.
(b) Quick Closing Valve Operation in Fire Scenarios:
(i) Fire in the Machinery Space:
In this scenario, the quick closing valve plays a crucial role in isolating the fuel source and preventing the fire from spreading. Here’s how it operates:
- Heat Detectors or Fire Alarm: Heat detectors or a fire alarm system within the machinery space would trigger a signal.
- Remote Activation: The fire alarm signal activates the remote closing mechanism of the quick closing valve (e.g., hydraulic, pneumatic, or solenoid).
- Valve Closure: The remote activation pushes a piston or releases pressurized air/fluid, forcing the valve shut rapidly. This isolates the fuel supply to the machinery space, preventing further feeding of the fire.
(ii) Fire Close to the Valve:
If a fire occurs near the quick closing valve itself (e.g., due to a fuel line leak), the valve’s operation becomes even more critical. Here’s what might happen:
- Heat Exposure: The intense heat from the fire could potentially melt or damage the electrical wiring or control mechanisms for remote actuation (if applicable).
- Manual override: In such cases, the valve design typically incorporates a manual override feature. This allows firefighters or personnel on-site to manually close the valve using a lever or wheel mechanism, even if the remote actuation system is compromised by the fire.
- Automatic Closure (Optional): Some quick closing valves may have built-in temperature sensors or fusible links. When exposed to excessive heat from a nearby fire, these mechanisms trigger an automatic closure of the valve, isolating the fuel source without relying on remote activation.
Note: The specific operation and fail-safe mechanisms of quick closing valves may vary depending on the valve design, fire detection system, and manufacturer’s specifications.