Backflow Prevention Practice Exam

What condition can cause a backflow preventer to fail?

1. Excessive pressure in the supply line

2. Increased atmospheric pressure

3. Air contamination

4. Extreme cold temperatures

The correct answer is: Excessive pressure in the supply line

Excessive pressure in the supply line is a significant factor that can lead to the failure of a backflow preventer. Backflow preventers are designed to maintain a specific pressure differential and operate properly within certain pressure ranges. When there is an excessive amount of pressure in the supply line, it can overwhelm the internal mechanisms of the backflow preventer, causing it to malfunction or even fail entirely. This can result in the potential for contaminated water to flow back into the clean water supply, which poses serious health risks. Other conditions, such as increased atmospheric pressure, air contamination, and extreme cold temperatures, typically do not directly cause a backflow preventer to fail in the same way. Increased atmospheric pressure may have more of an indirect effect, but it is not a primary cause of failure. Air contamination may affect water quality but doesn't specifically lead to mechanical failure of the backflow system, and extreme cold temperatures might lead to freezing issues rather than directly compromising the backflow preventer's function.