A venous access port assembly (10) having a housing base (28) with a discharge stem (16), a septum (14) and a cap (36). An interior reservoir (22) is defined by a well (30) in the housing base and the bottom surface of the septum, and a passageway (20) extends from the reservoir through the discharge stem (16). The cap (36) is secured to the housing base (28) and securely retains the septum in the assembly (10), compressing an annular flange (44) of the septum against a septum seat (46) of the housing base. Horizontal ribs on the interior of the cap snap into complementary grooves on the side wall of the housing base to mechanically lock together the cap and housing base during curing of the solvent bonding agent. The cap (48) is mechanically secured to the housing base (28) as well as being bonded thereto. Crush ribs (72) on the interior surface (68) of the cap (36), precisely center the cap about the housing base during assembly and compensating for manufacturing tolerances.
