What are the three rules in plumbing?

The three rules in plumbing play a crucial role in the design and function of plumbing systems. The correct answer highlights the principles that guide plumbing installation and functionality.

The first part of the rule, "Hot left, cold right," pertains to the standard practice in plumbing where hot water is typically supplied from the left side of a sink or tap, and cold water from the right side. This consistency helps users easily identify which side provides which temperature of water.

The second part, "sewage does not flow uphill," addresses the fundamental principle that wastewater and sewage must be directed downhill for proper drainage. This gravity-based flow is essential to prevent clogs and ensure efficient waste removal from buildings and properties.

By adhering to these rules, plumbing systems can be installed with a clearer understanding of flow patterns, temperature indications, and drainage requirements, thereby enhancing safety and functionality for users and the overall system infrastructure.