The distance between the end of the water supply pipe and the sink should be how many times the diameter of the supply pipe?

The correct distance between the end of the water supply pipe and the sink is ideally two times the diameter of the supply pipe. This guideline is rooted in the principles of plumbing and sanitation to ensure that water supply systems maintain adequate flow and prevent any potential contamination.

Maintaining a distance that is twice the diameter helps to minimize the risk of backflow or cross-contamination, which can occur if there are sudden changes in pressure within the system. By ensuring this separation, the design helps to uphold safe drinking water standards and ensures that harmful substances do not enter the water supply from the drain or sink area.

This principle is part of broader plumbing codes and standards that focus on hygiene and the safety of water supplies, ultimately contributing to public health.