Red Seal Plumbing Practice Exam

Which manufacturing method produces the strongest pipe?

1. Molded

2. Welded

3. Extruded

4. Cast

The correct answer is: Extruded

Extruded manufacturing produces the strongest pipe because the process involves pushing molten metal through a die to form a uniform shape. This creates a pipe with fewer weak points and potential weak spots, making it a more durable option. In contrast, molded pipes are made by injecting plastic into a pre-made mold, creating seams and joints that can decrease strength. Welded pipes are made by joining separate pieces of metal, which can lead to weaker spots along the joints. Cast manufacturing involves pouring molten metal into a mold, often resulting in an uneven and less structurally sound pipe. Therefore, extruded pipes are the strongest option compared to the other methods listed.