Abstract: A sealing assembly is releasably disposed on a hanger suspending a string of casing or tubing into a well. A shoulder on the hanger engages a seat in the bore of the wellhead and has passages therethrough for connecting the annular spaces above and below the seat. The seal assembly is lowered into the upper annular space around the hanger to close the annulus. The assembly includes a first tubular body threadingly connectable to the hanger, an outer load ring, an inner load ring, an inner packing ring disposed between the outer load ring and inner load ring, an inner retainer ring, and an outer packing ring disposed between the inner load ring and retainer ring. The inner packing ring singly engages the hanger and the outer packing ring singly engages the head. Such sealing occurs in series. The entire sealing force is applied through the outer diameter and inner diameter seal elements with the lower seal being loaded first.