Vessel drainage ball cock - has bolt through housing engaging with nut bearing against vessel bottom

摘要

The system secures a ball-type drain cock to a vessel esp. a thin-walled one, it being secured in a hole by a screw union, while its outlet is directed sideways from the vessel centre line. In the housing (1) upstream of the plug (2) is a through drilling (6) intersecting the straight flow passage (5), with a sealing face at one end bearing against the vessel bottom (8). A headed bolt (7, 9) passes through the drilling, its head forming a seal against the face of the housing furthest from the vessel bottom, while its shank extends through the vessel drain hole (10) to engage in a nut (11) bearing against the inside of the bottom. The drain hole and housing drilling are of larger diameter than the bolt shank, so that a concentric annular passage is formed round the latter.