Butt welding, also known as butt fusion welding, is a method used to join two polyethylene (PE) pipes by heating their ends and pressing them together under controlled pressure. The heated pipe ends melt and fuse into a single continuous piece of plastic, creating a joint that is as strong as, or stronger than, the pipe itself.

Butt welding is commonly used on larger diameter PE pipelines in water, gas, mining and civil infrastructure projects because it produces a strong, leak-free connection without the need for additional fittings. The process requires specialised fusion equipment and trained operators to ensure the correct heating, alignment, pressure and cooling times are achieved.