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Required Delivered Density (RDD)

The Required Delivered Density (RDD) test methods evaluate the necessary amount of applied water density to establish control or supression of a given fire challenge. Almost any commodity can be positioned in various storage array configurations (i.e. rack, palletized, etc.) and set aflame.

The Required Delivered Density (RDD) test methods evaluate the necessary amount of applied water density to establish control or supression of a given fire challenge. Almost any commodity can be positioned in various storage array configurations (i.e. rack, palletized, etc.) and set aflame.

A 25-ft diameter calorimeter hood then measures the total and convective heat release rate from products of combustion. The total heat release rate is measured using oxygen consumption principles. The convective heat release rate is measured using a thermocouple and volumetric flow-rate information. The calorimeter is capable of measuring heat release rates exceeding 10 megawatts with an exhaust of 60,000 CFM.

Water application is started when a fire model indicates sprinkler activation. Some of the parameters used in the fire model include: sprinkler activation temperature, sprinkler Response Time Index (RTI), radial distance of sprinkler to center of fire, distance of ceiling to top of commodity and number of storage tiers. Water is then applied evenly over the top of the burning commodity through the use of full cone pattern spray nozzles.

Test Standards

  • NFPA 13 -- Installation of Sprinkler Systems
  • UL 2335 -- Fire Tests of Storage Pallets

Applications

  • Commodity Classification -- Classifies a product or packaging system in rack storage arrangements per National fire safety Association (NFPA) 13 requirements
  • Special Service Investigations
  • Pallet Classification -- Measures fire performance of storage pallets in rack storage arrangements

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