Abstract: The invention features a manifold that includes two cylindrical ports and a cavity that connects to a fluid line. The ports both have the same cross-sectional area, and the center axes of the ports are oriented at the same angle with respect to the axis of the cavity. The ports couple to the cavity through separate transition regions, one of the transition regions coupling to a region at one end of the cavity that is circular in cross-section, and the other transition region coupling to an aperture disposed in a wall of the cavity. Both transition regions provide continuous fluid flow paths to the respective ports.