HDPE pipe is butt fused together using a fusion welder (below), welding machines vary depending on the Outside Diameter (OD) of the pipe to be welded. The pipe pieces are held by a clamping device. Large diameter pipe may require hoisting assistance such as an excavator or crane. Once the pipe is clamped, the ends are “faced” with a machining tool to establish a clean and parallel mating surface, perpendicular to the centreline of each pipe.
A heating plate is inserted between the faced ends, and then the pipe is drawn together against the heating plate. A melt pattern that penetrates into the pipes is formed around both pipe ends. Once the correct temperature is reached, the heating plate is quickly removed, and the heated ends are drawn together with specified force. The specified force on the joint must be continuous, and held until the joint cools. A small melt bead forms at the joint. Upon completion, the fused pipe is removed from the welding machine. Depending on the application that the pipe is being used for, the internal bead can be removed.