BELLING MACHINE FOR FORMING SOCKETS ON THE ENDS OF PIPES MADE OF THERMOPLASTIC MATERIAL AND METHOD OF FORMING A SOCKET AT THE END OF A PIPE MADE OF THERMOPLASTIC MATERIAL

摘要

In a belling machine and in a method of forming a socket at the heated end of a pipe, an end of a pipe made of thermoplastic material on which a socket is to be formed is heated until it is in a deformable state, inserted in a forming chamber and formed into a socket shape. Process air, taken from a compressed air source, is conveyed into an evaporator of a refrigerating machine using a refrigerant recirculating in a closed circuit and passes through the evaporator, resulting in transfer of heat from the process air to the refrigerant inside the evaporator. The process air is then conveyed to the forming chamber through an inlet, at least to cool the material of the end of the pipe at least by means of a process air flow inside the forming chamber.