Abstract: A coupler joint (10) which includes a hollow cylindrical portion (11) opened at its opposite ends and a flange (12) disposed along the circumference of the cylindrical portion (11) near the longitudinal center to be interposed between a dialyzer connector (21) and a coupler (30) so as to be in liquid tight engagement; one side of the flange (12) of the coupler joint 10 being in liquid-tight abutment with an opening (22) of the connector (21) of the dialyzer (20), and the other side of the flange (12) being in liquid-tight abutment with the a seal surface 31 of the coupler (30). Accordingly, a dialysis solution does not collect in a concave groove (32) which accommodates an O-ring (40) of the coupler (30), and proliferation of bacteria can be prevented.

Abstract: A coupler joint 10 which includes a hollow cylindrical portion 11 opened at its opposite ends and a flange 12 disposed along the circumference of the cylindrical portion 11 near the longitudinal center to be interposed between a dialyzer connector 21 and a coupler 30 so as to be in liquid tight engagement; one side of the flange 12 of the coupler joint 10 being in liquid-tight abutment with an opening 22 of the connector 21 of the dialyzer 20, and the other side of the flange 12 being in liquid-tight abutment with the a seal surface 31 of the coupler 30. Accordingly, a dialysis solution does not collect in a concave groove 32 which accommodates an O-ring 40 of the coupler 30, and proliferation of bacteria can be prevented.