【Daily Question】Utilities - Water Supply and Drainage - 20191221

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A four-story commercial building is equipped with a wet automatic sprinkler system; 1,200 upright sprinklers are installed above the ceiling, 2,600 ceiling-mounted sprinklers are installed below the ceiling, and 350 wall-mounted sprinklers are installed in certain rooms. Therefore, this building requires ( ) alarm valves. A.2 B.4 C.5 D.6 Answer: B According to Article 6.2.3 of the current Code for Design of Sprinkler Systems: when spray heads installed on the distribution branches serve both the area below and above the protected ceiling, only the number of spray heads on the side with more heads shall be counted toward the total number of heads controlled by the alarm valve assembly. In this case, there are 1,200 sprinklers above the ceiling and 2,600 sprinklers below it; therefore, the number of ceiling sprinklers controlled by the alarm valve assembly is 2,600. The total number of nozzles controlled by the alarm valve assembly is 21,600 + 350 = 29,500.