【Daily Question】Utilities - Water Supply and Drainage - 20191010
Thread Content
To prevent backflow contamination, the minimum air gap between the outlet of the faucet connected to the sanitary fixture and the overflow edge of that fixture must be no less than ( ). A. 2 times the diameter of the outlet B. 2.5 times the diameter of the outlet C. The diameter of the outlet D. 1.5 times the diameter of the outlet. The correct answer is B. According to Article 3.2.4, Paragraph 2 of the current Code for Design of Building Water Supply and Drainage, B is correct. The air gap should not be too small, as this may lead to backflow contamination.
B. 2.5 times the outlet diameter