CONVENTIONAL FIRE SPRINKLERS

Product Description

The mechanism is surprisingly simple and relies on a heat-sensitive element:

• Glass Bulb: A small vial filled with a heat-sensitive liquid. As heat rises, the liquid expands and shatters the glass, releasing the water seal.

• Fusible Link: Two pieces of metal held together by a solder with a specific melting point. When the solder melts, the link separates and the water flows.

• System Configurations

  Conventional sprinklers are integrated into four primary system types:

  1. Wet Pipe: The most common system. Pipes are always filled with pressurized water. Response is immediate.

  2. Dry Pipe: Pipes are filled with pressurized air or nitrogen. Water is held back by a valve. Used in unheated buildings (like parking garages) where pipes might freeze.

  3. Pre-Action: Requires two "triggers"a smoke/heat detector and the sprinkler head activationbefore water flows. Common in data centers to prevent accidental water damage.

  4. Deluge: All sprinkler heads are open (no heat elements). When triggered, water flows through every head simultaneously. Used in high-hazard areas like chemical plants.

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  Key Technical Specs

  • Temperature Ratings: Standard heads usually trigger at 68C (155F), though high-temp versions for kitchens or industrial areas can go up to 141C (286F) or higher.

  • Response Time Index (RTI): * Standard Response: Thicker glass bulbs (5mm), used for property protection.

    • Quick Response (QR): Thinner bulbs (3mm), used for life safety in residential or high-occupancy areas.

  • K-Factor: This refers to the orifice size. A standard sprinkler usually has a K-factor of 5.6, which determines how many gallons per minute (GPM) it discharges per square inch of pressure.

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  Maintenance & Compliance

  To ensure a conventional system remains functional, it generally requires:

  • Annual Inspections: Checking for painted-over heads, corrosion, or physical damage.

  • Obstruction Check: Ensuring no storage or shelving is within 18 inches of the sprinkler head.

  • Spare Head Cabinet: Codes typically require a box on-site containing spare heads and the specific wrench needed to install them.