No bead inside the pipe
In the case of butt-fusion, both the pipe surfaces are heated by using a heating plate because of which a bead is generated on the outer and inner surfaces of the joint. This may cause a reduction in flow-rates and may also lead to joints that are susceptible to cracks and breakages. Electrofusion is a fully automated process where the jointing happens on account of the electricity that is passed from the internal surface of the fitting; hence there is no bead generated in the pipes.