Rhode Island Journeyman Plumber Practice Exam

The abbreviation DFU stands for Drainage Fixture Unit. This term is crucial in plumbing design and analysis, as it represents a standardized measurement used to quantify the probable discharge of a plumbing fixture to the drainage system. Each type of fixture—such as sinks, toilets, and bathtubs—has a specific DFU value, which helps plumbers and engineers estimate the total load on a drainage system. This calculation supports the sizing of pipes and assures that the drainage system can effectively handle the expected flow without risking blockages or overflow. Understanding DFUs is vital for ensuring compliant and functional plumbing installations that meet building codes and standards.