A hemostatic valve device for use in inserting an interventional device into a body lumen of patient is provided. The valve device includes a housing that defines a cavity between first and second end openings. A valve structure is disposed within the cavity, and defines a variable diameter channel for receiving the interventional device. The valve structure can include discrete layers of material, such as a sealing layer and a contractible layer such as a biaxial braided layer. The end of the valve structure is movable relative to the fixed end so that the longitudinal passageway of the valve structure varies in diameter and axial length to form a seal against an interventional device inserted within the passageway. An operable element is coupled to the movable end and is actuated by the end user to open and close the valve structure.