What is the minimum diameter size limitation for branch drainage lines?

The minimum diameter size limitation for branch drainage lines is established to ensure adequate flow and to minimize the risk of blockages. A diameter of 50 mm is specified as the smallest allowable size for these lines in the plumbing code. This size facilitates effective drainage for typical residential fixtures and appliances, which is essential for maintaining hygiene and preventing backflow or overflow issues.

Using a pipe size smaller than this limit, such as 25 mm or 40 mm, could lead to increased chances of clogging and reduced flow capacity, ultimately compromising the performance of the drainage system. Therefore, the 50 mm requirement ensures that branch drainage lines can efficiently transport wastewater without causing operational problems.