| 摘要 |
The specification discloses an improved removable closure assembly (28) for use in feedwater heater or other pressure vessels requiring periodic internal access thereto for service, etc. The closure assembly (28) includes an o-ring seal (54) seated in a groove (58) chamfered into the outer edge of one end of a cylindrical cover (30) disposed in the open end of the channel or casing (12) of the pressure vessel. A compression ring (56) is disposed between the cover (30) and a split retaining ring (36) which are drawn together by bolts (60). The compression ring (56) overlies the o-ring (54) and a portion of the cover (30) so that only a portion of the compression force is transmitted through the o-ring, whereby an effective seal is provided without undue deformation such that the closure assembly (28) can be readily disassembled and removed, if desired. In a second embodiment, the closure assembly (66) incorporates a holding ring (68) which is secured by the bolts (70, 72) to the cover (30) over the retaining ring (36') and compression ring (56').
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