PE pipe joining methods include mechanical fittings and heat fusion. Which option listed is NOT a heat fusion method?

• A. Mechanical fittings
• B. Heat fusion
• C. Stub ends
• D. Thermally fused joints

Answer: (A)

The key idea is distinguishing joining methods that use heat from those that don’t. Heat fusion relies on heating the PE pipe ends and pressing them together so the plastic fuses into a single piece. Examples include butt fusion, socket fusion, and electrofusion—the joints created are thermally fused joints.

Mechanical fittings, on the other hand, join pipes without melting them. They clamp, grip, or compress the pipe ends with a fitting to form the connection. That’s why this option is not a heat fusion method.

Stub ends are simply a type of fitting used in PE piping; they aren’t themselves a specific heat-fusion technique. And thermally fused joints are explicitly the products of heat fusion. So the option that does not describe a heat fusion method is the mechanical fittings approach.