Abstract: The present invention provides a valve that controls a flow of gas or solid objects through a pipe, and particularly a z-valve used in an elevated rail transportation system. The valve includes vanes hinged to a valve stem that fold into a z-shape and retract into the valve body when the valve is open. A valve cap positioned at the top of the valve stem matches the contour of the inner surface of the pipe, allowing unobstructed flow. When the valve is closed, the valve stem is elevated into the interior of the pipe and the valve cap rotates 90° to match the contour at the top, providing a seal. The vanes extend from the z-shape to completely block a cross-section of the pipe, stopping the flow. The flow may be modulated by varying the extension of the vanes to allow a portion of the flow to pass the valve.

Abstract: The present invention provides a valve that controls a flow of gas or solid objects through a pipe, and particularly a z-valve used in an elevated rail transportation system. The valve includes vanes hinged to a valve stem that fold into a z-shape and retract into the valve body when the valve is open. A valve cap positioned at the top of the valve stem matches the contour of the inner surface of the pipe, allowing unobstructed flow. When the valve is closed, the valve stem is elevated into the interior of the pipe and the valve cap rotates 90° to match the contour at the top, providing a seal. The vanes extend from the z-shape to completely block a cross-section of the pipe, stopping the flow. The flow may be modulated by varying the extension of the vanes to allow a portion of the flow to pass the valve.