Sleeve part of a pipe joint wherein the sleeve part includes a chamber space, into which the opposing butt ends of the pipe parts to be connected together are placed such that the sleeve part extends a distance from the point of connection of the pipe parts to be connected together on top of both pipe parts. The sleeve part includes heating member, such as resistance wires. As a consequence of the heating of the resistance wires a joint forms between the sleeve part and the pipe parts. An inspection aperture is formed in the sleeve part through the wall of the sleeve part from the exterior to the interior to a point where the positioning of the opposing butt end surfaces of the pipe parts to be connected together can be verified. The invention also relates to a pipe joint.