| 摘要 |
The proposed valve comprises valve body (10) which defines a through passageway (16) and a constriction (11) at an intermediate portion of the passageway (16), and a valve pin (20) slideably disposed in the passageway and carrying a sealing member (40) positioned to bear against a sealing surface (15) defined by the constriction (11) to seal the passageway (16), wherein the valve pin (20) defines a flange (23) adjacent the sealing member (40), said flange (23) having an external diameter (A) slightly larger than the minimum diameter (B) of the passageway (16) at the constriction (11) such that the flange (23) is sized to pass through the constriction (11) without destruction of the pin (20) or the valve body (10). The improvement foresees: means for defining a step (14) in the valve body (10) around the passageway (16) at the constriction adjacent to the sealing surface (15); and means for defining a shelf (23a) on the flange (23) shaped and positioned to engage the step (14) to prevent the pin (20) from being expelled out of the passageway (16). |
