| 摘要 |
The plug ball (2) is made up of hollow mouldings (11-14) in ring form joined together via integrated ceramic welds (16) fitted out with supplementary positive components. The ring holes join up to form the flow channel (3), the plug specifically composed of outer end rings (11,14) and centre ring (15). The ring has diametrically opposed bearing journals etc. (17,18) or other connections for the actuating spindle and the centre ring is made up of two ring discs (12,13) joined by a weld etc. The rings are preferably in partial ring form so as to provide the plug inlet and outlet respectively and all the mouldings are formed without stress of any kind. The rings are typically slip-cast or made from powder, using ceramic slip as appropriate which has then to be dewatered, sintered and machined etc. The welds can also be soldered if so required, in view of their freedom from mechanical loading.
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