5.11 Water distribution and droplet size tests
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Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.800(19) – Revised Guidelines for Approval of Sprinkler Systems Equivalent to that Referred to in SOLAS Regulation II-2/12 – (Adopted on 23 November 1995) - Appendix 1 - Component Manufacturing Standards for Water Mist Nozzles - 5 Methods Of Test [7] - 5.11 Water distribution and droplet size tests

5.11 Water distribution and droplet size tests

Parent topic: 5 Methods Of Test [7]

5.11.1 Water distribution (see 4.4.2 )

 The tests should be conducted in a test chamber of minimum dimensions 7 m x 7 m or 300% of the maximum design area being tested, whichever is greater. For standard automatic nozzles, a single open nozzle should be installed and then four open nozzles of the same type arranged in a square, at maximum spacings specified by the manufacturer, on piping prepared for this purpose. For pilot type nozzles, a single nozzle should be installed and then the maximum number of slave nozzles at their maximum spacings, specified in the Manufacturer Design and Installation Instructions.

 The distance between the ceiling and the distribution plate should be 50 mm for upright nozzles and 275 mm for pendent nozzles. For nozzles without distribution plates, the distances should be measured from the ceiling to the highest nozzle outlet.

 Recessed, flush and concealed type nozzles should be mounted in a false ceiling of dimensions not less than 6 m x 6 m and arranged symmetrically in the test chamber. The nozzles should be fitted directly into the horizontal pipework by means of T or elbow fittings.

 The water discharge distribution in the protected area below a single nozzle and between the multiple nozzles should be collected and measured by means of square measuring containers nominally 300 mm on a side. The distance between the nozzles and the upper edge of the measuring containers should be the maximum specified by the manufacturer. The measuring containers should be positioned centrally, beneath the single nozzle and beneath the multiple nozzles.

 The nozzles should be discharged both at the minimum operating and rated working pressures specified by the manufacturer and the minimum and maximum installation heights specified by the manufacturer.

 The water should be collected for at least 10 min to assist in characterizing nozzle performance.

5.11.2 Water droplet size (see 4.4.3 )

 The mean water droplet diameters, velocities, droplet size distribution, number density and volume flux should be determined at both the minimum and maximum flow rates specified by the manufacturer. Once the data is gathered, the method of the "Standard Practice for Determining Data Criteria and Processing for Liquid Drop Size Analysis" (ASTM E799-92) will be used to determine the appropriate sample size, class size widths, characteristic drop sizes and measured dispersion of the drop size distribution. This data should be taken at various points within the spray distribution as described in 4.4.3.

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