Arizona Plumbing Practice Exam

Polybutylene pipe may be used in hot water piping of hydronic heating systems when the water in the pipe does not exceed:

1. 140 degrees at 100 psi

2. 160 degrees at 100 psi

3. 180 degrees at 100 psi

4. 200 degrees at 100 psi

The correct answer is: 180 degrees at 100 psi

Polybutylene pipe is a type of plastic piping that has specific temperature and pressure limits for safe use, particularly in hot water applications such as hydronic heating systems. The correct answer indicates that polybutylene pipe can safely handle temperatures up to 180 degrees Fahrenheit when the pressure is maintained at 100 psi. This maximum temperature threshold is significant because exceeding it could lead to the material degrading over time, which may result in leaks, failures, or even pipe bursts. Hydronic heating systems often operate at elevated temperatures, so understanding the limits of the materials used is crucial for ensuring long-term reliability and safety. In this context, the other options suggest higher temperature limits, which polybutylene does not safely support. Using the pipe beyond its recommended maximum could compromise the integrity of the piping system, highlighting the importance of adhering to manufacturer guidelines regarding temperature and pressure limits.