A refractory pouring tube comprising an inner surface defining a first portion of a pouring channel and a first contact face capable of bearing against a second contact face of a second refractory component defining an adjacent portion of the pouring channel and provided with an injection groove capable of forming with the first contact face an injection channel substantially encircling the pouring channel, the pouring tube adapted to be displaced in a predefined trajectory along which the first contact face slides and remains in bearing contact against the second contact face while the first portion of the pouring channel intercepts a determinant part of the injection groove, the first contact face comprising an additional groove and a second groove, the additional groove located proximate to the determinate part and communicating with the injection groove at least on either side of the determinate part, and the second groove is essentially parallel to the additional groove and is located, relative to the additional groove, on the other side of the pouring channel.