All of the following types of pipe are thermoplastic EXCEPT?

The type of pipe that is not classified as thermoplastic in this question is fiberglass. Fiberglass is a composite material made from a polymer matrix reinforced with glass fibers. While it does exhibit some plastic characteristics, it is not considered a thermoplastic. Instead, fiberglass is classified as a thermosetting material, which means that once it is cured, it cannot be remelted or reshaped through heating.

On the other hand, the other options—Polyvinyl Chloride (PVC), Polyethylene, and Acrylonitrile - Butadiene - Styrene (ABS)—are all thermoplastics. These materials become pliable or moldable at a certain elevated temperature and solidify upon cooling, which is a defining characteristic of thermoplastics. They are widely used in various applications due to their flexibility, strength, and resistance to chemicals. Understanding the fundamental differences between thermoplastic and thermosetting materials is crucial in selecting the appropriate pipe type for specific applications in pipefitting and other construction-related tasks.