Flange valve having improved sealing characteristics and wear indicator

摘要

The specification discloses a flange valve having a metal valve body with a longitudinal central passage therethrough and annular flanges extending outwardly from the ends thereof. A truncated ellipsoid valve member is located in the central portion of the passage, the ellipsoid member having major and minor axes and being truncated at the opposite ends of the major axes. An aperture is formed through the ellipsoid member along the major axis. Annular resilient seats are disposed on opposing sides of the valve member to provide sealing between the interior of the valve body and the exterior of the valve member. A pair of removable annular liners are dimensioned to closely fit within opposite ends of the central passage of the valve body and include end portions abutting the resilient seats. The liners are constructed from non-corrosive material to prevent corrosion of the valve body. A handle is provided to rotate the valve member between open and closed positions, the major axis and the aperture being aligned with the passage in the open position and the seats being deformed by the valve member in the open position to provide improved sealing. A wear detector is provided in the walls of the valve body in order to provide an indication of when the valve body wears to a predetermined degree.