An improved valve port system provides blood access in a patient through a subcutaneous fluid flow conduit during a dialysis procedure. The system includes several elements, including a engagement member defined by a tubular body having a proximal end, a distal end and a tubular lumen therebetween. The distal end has a tapered bevel defined thereat and a tapered protrusion proximate thereto defined upon an exterior surface of the tubular body. In addition, the system provides a dialysis port member having a housing with a generally cylindrical valve rotatably positioned therein. The valve includes an open end, a closed end and an orifice near the closed end. The valve further includes a longitudinal groove defined along an interior surface thereof. The groove, which is capable of being in registry with the protrusion, is coincident with the protrusion so as to intussuscept the protrusion therein. In this manner, rotation of the engagement member effects rotation of the valve between an open position wherein the orifice is in fluid communication with the fluid flow conduit and a closed position wherein fluid communication between the orifice and the conduit is precluded.