Arizona Plumbing Practice Exam 2025 – Complete Preparation Guide

The most commonly used material for residential water supply piping is copper because of its excellent properties that make it suitable for plumbing applications. Copper is highly durable, resistant to corrosion, and has a long lifespan, which is essential for maintaining the integrity of plumbing systems. It is also non-toxic, making it safe for drinking water.

Additionally, copper piping can handle high temperatures and is less likely to be affected by changes in pressure within the plumbing system. Its natural antimicrobial properties can also contribute to maintaining cleaner water. The ease of installation, along with the ability to be soldered or brazed, further enhances its practicality in residential settings.

While other materials like polyvinyl chloride (PVC) are commonly used for drainage and waste systems, they are not typically used for pressurized water supply lines in the same way that copper is. Galvanized steel and cast iron may have been used in the past but have largely fallen out of favor for water supply due to issues with corrosion and weight, making copper the preferred choice in modern plumbing.