A control valve comprising: a body (16, 82) defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet; a valve seat ring having an outwardly extending flange, the valve seat ring being disposed within the valve body (16, 82) and defining an orifice through which the fluid flow path passes; a throttling element configured to engage the valve seat ring to control fluid flow through the control valve; and a retainer (14, 80) coupled to the valve body (16, 82) and engaging the valve seat ring to retain the valve seat ring in position within the valve body (16, 82) such that a seal is formed between a bottom surface of the flange of the valve seat ring and a corresponding surface of the valve body (16, 82) to prevent flow past the valve seat ring external to the valve seat ring orifice, wherein the retainer (14, 80) is configured to be disposed about the valve seat ring, the retainer (14, 80) comprising an inwardly extending ring having a plurality of holes therethrough and a plurality of bolts each disposed through a corresponding one of the holes and engaging the valve seat ring to force the bottom surface of the flange of the valve seat ring into engagement with the corresponding surface of the valve body (16, 82) to form the seal; characterized in that the inner diameter of the inwardly extending annular ring of the of the retainer (14, 80) is larger than the outer diameter of the valve seat ring above the outer flange; and a valve cage is disposed within and coupled to the valve body and engaging the valve seat ring, wherein the valve cage defines an interior bore and at least one passage extending through the cage and through which the fluid path passes and wherein the throttling element has an outer surface sized for slidable insertion into the interior bore of the cage. a body (16, 82) defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet; a valve seat ring having an outwardly extending flange, the valve seat ring being disposed within the valve body (16, 82) and defining an orifice through which the fluid flow path passes; a throttling element configured to engage the valve seat ring to control fluid flow through the control valve; and a retainer (14, 80) coupled to the valve body (16, 82) and engaging the valve seat ring to retain the valve seat ring in position within the valve body (16, 82) such that a seal is formed between a bottom surface of the flange of the valve seat ring and a corresponding surface of the valve body (16, 82) to prevent flow past the valve seat ring external to the valve seat ring orifice, wherein the retainer (14, 80) is configured to be disposed about the valve seat ring, the retainer (14, 80) comprising an inwardly extending ring having a plurality of holes therethrough and a plurality of bolts each disposed through a corresponding one of the holes and engaging the valve seat ring to force the bottom surface of the flange of the valve seat ring into engagement with the corresponding surface of the valve body (16, 82) to form the seal; characterized in that the inner diameter of the inwardly extending annular ring of the of the retainer (14, 80) is larger than the outer diameter of the valve seat ring above the outer flange; and a valve cage is disposed within and coupled to the valve body and engaging the valve seat ring, wherein the valve cage defines an interior bore and at least one passage extending through the cage and through which the fluid path passes and wherein the throttling element has an outer surface sized for slidable insertion into the interior bore of the cage.