Device for internal cooling of extruded thermoplastics pipes

The invention relates to a method and a device for cooling an extruded thermoplastics pipe (1) by directing a gaseous cooling medium tangentially towards the inner surface of the thermoplastics pipe (1) along its whole periphery, whereby the interior of the thermoplastics pipe (1) is divided by means of a protecting pipe (8) into an outer ring-shaped flow channel (9) for the cooling medium along the inner surface of the thermoplastics pipe (1), and a central return channel (10) through which a part of the cooling medium is intended to be sucked back influenced by the flow of cooling medium in the outer ring-shaped flow channel (9), and to be redirected towards the inner surface of the thermoplastics pipe (1). The invention is characterized in that the cooling medium is air, and that there is a cooling equipment (6) mounted in the return channel (10), whereby temperature and flow rate at least of the cooling water led to the cooling equipment (6) and possibly also of the cooling air which is fed into the thermoplastics pipe (1) are adjusted and controlled based on dimension and extrusion rate of the thermoplastics pipe (1) being manufactured.