| 摘要 |
The valve closure element has an annular peripheral groove opening outwardly onto the periphery of the closure element. An annular sealing element has an annular heel portion disposed in the groove. The latter has an inner end face whose diameter is less than the inside diameter of the heel portion. The groove is defined laterally by two confronting annular faces of the closure element which have a substantially rectilinear generatrix and grip the heel portion so as to prevent relative movement of the heel portion and closure element. |
