A sealing ring of elastic material, more particularly for a plug-in type pipe joint made up of two concentrically interfitting pipe elements of a mineral material in the case of which the sealing ring can be pre-assembled by insertion into the outer pipe element or socket before the insertion of the inner pipe element or spigot. The sealing ring has a substantially V-shaped axial section profile with the formation of two annular lips consisting of a support lip and a sealing lip. The sealing ring also has a sealing foot, which is opposite to the angle included by the support lip and the sealing lip and said sealing ring can be fixed by its sealing foot and/or by a holding part molded additionally on the sealing ring, by dint of an annular groove constructed in the inner wall of the socket in order to prevent axial displacement of the sealing ring in the insertion direction of the spigot. The sealing ring on insertion of the spigot into the socket can be inwardly axially tilted through the radial plane defined substantially by the sealing foot of the sealing ring in such a manner that the support lip and the sealing lip stand substantially symmetrically with respect to the radial plane. When the spigot is inserted the radial clamping and distortion of the sealing ring makes a sealing engagement with the external casing of the spigot with respect to external pressure, the sealing lip makes sealing engagement with the external casing of the spigot with respect to internal pressure and the sealing foot makes sealing engagement with the floor of the annular groove or on the inner wall of the socket with respect to internal and external pressure.