| 摘要 |
1535085 Valves DRESSER INDUSTRIES Inc 22 March 1976 [7 April 1975] 11463/76 Heading F2V In a butterfly valve gas leakage along a path between the polygonal shaft 16 and a journal 38 is prevented by a seal 48 surrounding the shaft and compressed between the chamfered end of the journal and the surface 46 of the hollow closure disc 22. The opposite end of the shaft is supported by a journal 28 and has a leakagepreventing seal 32, which if defective allows gas pressure to act on the end 60 of the shaft to further compress the seal 48 and prevent leakage to the outside. The journals are sealed to the body by three-lobe seals 34, 42, the latter of which can be packed with lubricant from the outside via passages (64, 66). Uncompressed the seal 48 has a chamfered surface 52 for cooperating with the journal and an annular rib 58 for co-operating with the surface 46 of the disc. Reference has been directed by the Comptroller to Specification 1,175,976.
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