Blocked ball valve.

摘要

The present invention relates to a ball valve having a housing (21) with an axial passageway (27) through the housing (21) providing fluid communication between first and second ends (23, 25) of the housing (21). A rotatable ball (33) is arranged within the axial passageway (27) for selectively opening and closing the axial passageway (27). A seal is arranged within the axial passageway (27) near the first end (23) of the housing (21) such that the seal is adapted to abut a surface on the rotatable ball (33). A blocking member (75) is provided for selectively preventing axial movement of the seal towards the first end (23) and for permitting axial movement of the seal towards the surface of the rotatable ball (33) independently of the blocking member (75). In a preferred embodiment, the seal is arranged on a seal carrier (67) which has an annular groove (73) in an outer peripheral surface. The blocking member (75) comprises an annular retaining ring (75) which is threadedly secured within the axial passageway (27) at the first end (23) of the housing (21) and is arranged in the annular groove (73) in the outer peripheral surface of the seal carrier (67). An external diameter of the annular groove (73) in the seal carrier (67) is less than an internal diameter of the annular retaining ring (75). A connecting sleeve (50) having a flange (49) at one end adapted to abut a radial surface (76) of the seal carrier (67) selectively urges the seal carrier (67) and the seal attached thereto into tight-fitting engagement with the surface of the rotatable ball (33) when a clamping nut (53) is secured to an outer peripheral surface of the housing (21) and urges the flange (49) of the connecting sleeve (50) into engagement with the seal carrier (67).