【Daily Question】Utilities - Water Supply and Drainage - 20200411

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Which of the following statements regarding the installation of hot water circulation pumps is in accordance with the current \"Code for Design of Building Water Supply and Drainage\"? A. The head of the circulation pump for semi-immediate water heaters should be equal to the sum of the head losses incurred as the circulating water passes through the supply and return pipe networks, plus the head loss associated with the water heater itself. B. Ordinary pipeline pumps should be used for hot water circulation pumps. C. The working pressure experienced by the pump casing must not be less than the sum of the hydrostatic pressure acting on the pump body and the pump’s head. D. There is no need to install a backup pump for the circulation pump. Answer: C. Option A does not comply with the provisions specified in Paragraph 2 of Article 5.5.10 of the current “Code for Design of Building Water Supply and Drainage Systems”; the head of the circulation pump for semi-immediate water heaters should indeed be equal to the sum of the head losses in the supply and return pipe networks, plus the head loss associated with the water heater. Option B does not comply with the provisions of Article 5.5.10, Paragraph 3, of the current Code for Design of Building Water Supply and Drainage. A pump specifically designed for hot water should be used for the hot water circulation pump. Option D does not comply with the provisions of Article 5.5.10, Paragraph 4, of the current Code for Design of Building Water Supply and Drainage Systems. A standby pump should be provided for the circulation pump. Option C does not comply with the provisions of Article 5.5.10, Paragraph 3, of the current Code for Design of Building Water Supply and Drainage. To prevent the hot water circulation pump from bursting due to excessive static pressure, the operating pressure acting on the pump casing should be determined by adding together the static pressure exerted on the pump casing and the head generated by the pump