Texas Tradesman Plumber-Limited License Practice Exam

The term 'negative pressure' in a plumbing system refers to a situation that can lead to backflow. When negative pressure occurs, it creates a vacuum effect in the system, which can draw water from a source, such as a sanitary waste system or sewer, back into clean water lines. This condition poses a risk to the safety and sanitation of the water supply, as it can cause contaminants to enter the potable water supply. It's essential for plumbing systems to be designed to prevent negative pressure situations through various means, such as properly installed air gaps and backflow prevention devices. Understanding this concept is vital for ensuring safe plumbing practices and maintaining the integrity of water quality in plumbing systems.