Process for the preparation of impact resistant conduit to.

Process for preparing a conduit comprising at least one layer composed of a polypropylene composition comprising a base resin nucleated beta propylene, wherein said method comprises the steps of: a) extrusion of the polypropylene composition at a temperature greater than 200, b) subsequent cooling of the extruded product with a cooling medium having a temperature of 5 ° c, and c) subsequent annealing of the extruded product with a temperature control medium having a temperature at least equal to the temperature of the cooling medium of step b).