Flaring unit for flaring PVC-O pipe, automatic flaring machine comprising same and method

Described is a unit (1) for flaring a pipe (T) made of a thermoplastic material of the PVC-O type, comprising:-a profiled pad (2) for deforming an end portion (E) of the pipe (T) made of thermoplastic material into a flaring shape, said pad (2) having a symmetrical longitudinal central axis (X1) and a region (3) for receiving an annular gasket (G), the annular gasket (G) is designed to be internally coupled with a pipe (T) made of a thermoplastic material; -an annular contact element (4) slidably adapted on said pad (2) so as to move in the direction of said longitudinal central axis (X1) between an advanced position (P1) and a withdrawn position (P2) of contact of the gasket (G); the unit (1) comprises:-first heating means (6) configured for heating the annular contact element (4) to a predetermined temperature so as to heat, by contact, an inner surface of an end portion (E) of the tube (T) fitted on the annular contact element (4); -second heating means (5) configured to externally heat said tube (T) made