Tear-away and non-tear-away sheath introducers for catheters, methods for making such introducers, and methods for using such introducers are described. The sheath introducers contain movable valves that are encapsulated in a movable housing that allows the valve to move along the axis of the introducer. As the movable valve and housing travel along the axis, a portion of the hub protrudes past the valve and is exposed. As well, the sheath introducers can also contain a stationary valve and housing that can be opened to expose a portion of the hub when a conduit penetrates the stationary valve. In both instances, the protruding portion of the hub contains a friction-free pathway for a catheter into the sheath introducer. The introducers can therefore be used with any catheter, regardless of the size or material, because of the reduced or eliminated frictional force between the catheter and introducer.