A seal assembly comprises: a first seat comprising: an axial portion extending circumferentially around a center axis and extending axially from a first end to a second end; a radial portion extending circumferentially around the axial portion and extending radially from the axial portion between the first end and the second end; and a cavity formed in the radial portion and extending circumferentially around the axial portion; and a second seat comprising: a radial segment extending circumferentially around the center axis and extending radially from an inner surface to an outer surface of the radial segment; and an axial segment extending circumferentially around the first end of the first seat, and extending axially from the radial segment to a distal end, a first seal ring extending circumferentially around the axial segment of the second seat and positioned axially between the radial portion of the first seat and the radial segment of the second seat; and a second seal ring extending circumferentially around the axial segment of the second seat and positioned axially between the first seal ring and the radial portion of the first seat; characterised in that the axial segment comprises a tapered outer surface that tapers radially inward toward the distal end, and in that the distal end is received in the cavity of the first seat. a first seat comprising: an axial portion extending circumferentially around a center axis and extending axially from a first end to a second end; a radial portion extending circumferentially around the axial portion and extending radially from the axial portion between the first end and the second end; and a cavity formed in the radial portion and extending circumferentially around the axial portion; and an axial portion extending circumferentially around a center axis and extending axially from a first end to a second end; a radial portion extending circumferentially around the axial portion and extending radially from the axial portion between the first end and the second end; and a cavity formed in the radial portion and extending circumferentially around the axial portion; and a second seat comprising: a radial segment extending circumferentially around the center axis and extending radially from an inner surface to an outer surface of the radial segment; and an axial segment extending circumferentially around the first end of the first seat, and extending axially from the radial segment to a distal end, a radial segment extending circumferentially around the center axis and extending radially from an inner surface to an outer surface of the radial segment; and an axial segment extending circumferentially around the first end of the first seat, and extending axially from the radial segment to a distal end, a first seal ring extending circumferentially around the axial segment of the second seat and positioned axially between the radial portion of the first seat and the radial segment of the second seat; and a second seal ring extending circumferentially around the axial segment of the second seat and positioned axially between the first seal ring and the radial portion of the first seat; characterised in that the axial segment comprises a tapered outer surface that tapers radially inward toward the distal end, and in that the distal end is received in the cavity of the first seat.