What does the term 'grade' refer to in plumbing?

The term 'grade' in plumbing specifically refers to the rate of slope of a sewer line. This is crucial in ensuring that wastewater flows efficiently through the pipes by utilizing gravity. A proper slope helps prevent clogs and provides adequate drainage, which is essential for maintaining a sanitary system. In plumbing code standards, maintaining the correct grade is necessary for compliance with health and safety regulations, as improper slope can lead to backflow or stagnant water, causing potential health hazards and plumbing failures.

Understanding grade is fundamental for plumbers in planning and installing sewer systems, as it directly affects the functionality and reliability of drainage systems.