A heating apparatus in an injection molding apparatus comprised of an injection molding machine that injects injection fluid to a heated manifold that distributes the injection fluid to one or downstream nozzles , the heating apparatus comprising: a heatable sleeve or jacket comprised of a sheet of highly heat conductive metal material, the sheet or jacket having opposing sheet edges, the sheet or jacket being bent or formed into a heating cylinder having a central channel having an interior circumferential wall surface and a selected longitudinal length (HL) extending from a downstream end to an upstream end of the heating cylinder , wherein the central channel is formed into a configuration wherein a selected nozzle is received within the central channel and the interior circumferential wall surface of the channel engages an outer circumferential wall surface of the selected nozzle , the sheet has opposing sheet edges that are disposed by the bending or forming into a select arrangement or position relative to each other upon reception of the selected nozzle within the central channel , the apparatus includes a stabilization ring or cylinder having a central ring channel having an inner ring circumferential surface , the stabilization ring or cylinder being adapted to receive a selected longitudinal portion (DL) of the downstream or distal end of the heating cylinder , characterised in that the stabilization ring or cylinder is adapted to engage or mate the inner ring circumferential surface with an outer surface of the heating cylinder extending along a predetermined length (PDL) of all or a portion of the selected longitudinal portion (DL) of the downstream or distal end of the heating cylinder , the predetermined length (PDL) of the selected longitudinal portion (DL) selected such that the opposing sheet edges of the sheet are disconnected over a selected portion (SPL; SPL1; SPL2; SPL3) of the longitudinal length (HL) of the heating cylinder . a heatable sleeve or jacket comprised of a sheet of highly heat conductive metal material, the sheet or jacket having opposing sheet edges, the sheet or jacket being bent or formed into a heating cylinder having a central channel having an interior circumferential wall surface and a selected longitudinal length (HL) extending from a downstream end to an upstream end of the heating cylinder , wherein the central channel is formed into a configuration wherein a selected nozzle is received within the central channel and the interior circumferential wall surface of the channel engages an outer circumferential wall surface of the selected nozzle , the sheet has opposing sheet edges that are disposed by the bending or forming into a select arrangement or position relative to each other upon reception of the selected nozzle within the central channel , the apparatus includes a stabilization ring or cylinder having a central ring channel having an inner ring circumferential surface , the stabilization ring or cylinder being adapted to receive a selected longitudinal portion (DL) of the downstream or distal end of the heating cylinder , characterised in that the stabilization ring or cylinder is adapted to engage or mate the inner ring circumferential surface with an outer surface of the heating cylinder extending along a predetermined length (PDL) of all or a portion of the selected longitudinal portion (DL) of the downstream or distal end of the heating cylinder , the predetermined length (PDL) of the selected longitudinal portion (DL) selected such that the opposing sheet edges of the sheet are disconnected over a selected portion (SPL; SPL1; SPL2; SPL3) of the longitudinal length (HL) of the heating cylinder . <EOS>