| 摘要 |
A spherical valve is provided with a valve body shaped as a spherical segment which is suspended rotatably in a valve housing according to a centre line of the sphere which is determined by the spherical closing surface of the spherical segment, which valve housing has a passageway which can be closed by means of the spherical segment, which passageway is delimited by a circular valve seating with a seal, which at least at its face which cooperates with the spherical segment is provided with a wear resistant layer which may be pressed onto the spherical segment, the spherical segment being rotatable between a closed position in which it sealingly rests against the seal, and an open position in which it is at least partly outside the passageway. The seal is a section which is expandable by means of an internal overpressure. |
