A connector assembly for connection and disconnection between ports of fluid lines for administering fluids into a human body from a route other than the oral route. The connector assembly includes a catheter dock, a cap removal dock, a fluid line dock, and a new cap dock. The catheter dock can receive an inlet port of a catheter secured by a catheter cap. The cap removal dock can aseptically remove the catheter cap from the inlet port. The catheter dock can be switched consecutively between the cap removal dock, the fluid line dock, and the new cap dock. Upon removal of the catheter cap, the catheter dock can be switched to the fluid line dock, and the fluid can flow from the fluid line to the catheter. Upon administering the liquid, the catheter dock can be switched from the fluid line dock to the new cap dock, wherein a new catheter cap is secured into the inlet port under aseptic conditions.