5.7 Heat exposure test [7.7]
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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] - 5.7 Heat exposure test [7.7]

5.7 Heat exposure test [7.7]

Parent topic: 5 Methods Of Test [7]

5.7.1 Glass bulb nozzles (see 4.9.1 )

 Glass bulb nozzles having nominal release temperatures less than or equal to 80°C should be heated in a water bath from a temperature of 20 ± 5°C to 20 ± 2°C below their nominal release temperature. The rate of increase of temperature should not exceed 20°C/min. High temperature oil, such as silicone oil should be used for higher temperature rated release elements.

 This temperature should then be increased at a rate of l °C/min to the temperature at which the gas bubble dissolves, or to a temperature 5°C lower than the nominal operating temperature, whichever is lower. The nozzle should be removed from the liquid bath and allowed to cool in air until the gas bubble has formed again. During the cooling period, the pointed end of the glass bulb (seal end) should be pointing downwards. This test should be performed four times on each of four nozzles.

5.7.2 All uncoated nozzles (see 4.9.2 ) [7.7.2]

 Twelve uncoated nozzles should be exposed for a period of 90 days to a high ambient temperature that is 11°C below the nominal rating or at the temperature shown in Table 4, whichever is lower, but not less than 49°C. If the service load is dependent on the service pressure, nozzles should be tested under the rated working pressure. After exposure, four of the nozzles should be subjected to the tests specified in 5.4.1, four nozzles to the test of 5.5.1, two at the minimum operating pressure and two at the rated working pressure, and four nozzles to the requirements of 4.3. If a nozzle fails the applicable requirements of a test, eight additional nozzles should be tested as described above and subjected to the test in which the failure was recorded. All eight nozzles should comply with the test requirements.

Table 4 Test Temperatures for Coated and Uncoated Nozzles

Values in °C
Nominal release temperature Uncoated nozzle test temperature Coated nozzle test temperature
57–60 49 49
61–77 52 49
78–107 79 66
108–149 121 107
150–191 149 149
192–246 191 191
247–302 246 246
303–343 302 302

5.7.3 Coated nozzles (see 4.9.3 ) [7.7.3]

 In addition to the exposure test of 5.7.2 in an uncoated version, 12 coated nozzles should be exposed to the test of 5.7.2 using the temperatures shown in Table 4 for coated nozzles.

 The test should be conducted for 90 days. During this period, the sample should be removed from the oven at intervals of approximately 7 days and allowed to cool for 2 h to 4 h. During this cooling period, the sample should be examined. After exposure, four of the nozzles should be subjected to the test specified in 5.4.1, four nozzles to the test of 5.5.1; two at the minimum operating pressure and two at the rated working pressure, and four nozzles to the requirements of 4.3.

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