What is the difference between CPVC and PVC pipes?

The primary distinction between CPVC and PVC pipes lies in their temperature resistance, making option A the correct choice. CPVC, or Chlorinated Polyvinyl Chloride, has been treated with additional chlorine, allowing it to endure higher temperatures, typically up to 200°F (93°C) for hot water applications. In contrast, traditional PVC, or Polyvinyl Chloride, is generally not recommended for hot water; its thermal limit is around 140°F (60°C). This characteristic makes CPVC suitable for both cold and hot water systems, while PVC is mainly designed for cold water and drainage applications.

The other options concerning flexibility, cost, and intended use are less accurate. While PVC is known for its flexibility when compared to some rigid materials, CPVC is also flexible, but to a slightly lesser degree due to its composition. Furthermore, CPVC is typically more expensive than PVC due to the extra processing it undergoes. Lastly, stating that PVC is intended only for drainage use does not encapsulate its adaptations, as PVC can also be used for various plumbing applications, including venting and cold-water distribution. Thus, the superior temperature tolerance of CPVC over PVC distinctly identifies A as the appropriate choice.