Abstract: The compressor comprises: a shell carrying a gas outlet tube and housing a cylinder cap having a gas outlet; and a plastic discharge tube having an inlet end and an outlet end respectively coupled to the gas outlet and to the gas outlet tube, at least one of said inlet and outlet ends being connected to a discharge part, defined at the gas outlet or at the gas outlet tube, by a connecting element having: a fixation portion, affixed inside the discharge part; an engaging portion fitted inside one end of the discharge tube and carrying a superficial indexing means acting against the discharge tube; and gripping means disposed between the indexing means and the fixation portion; and a retaining ring mounted around the discharge tube for compressing the latter, in order to spike, therein, the gripping means.