| 摘要 |
<p>A sight glass assembly includes a housing having an opening to receive the lens, the run of which is supported on the outside face by a radially inwardly projecting shoulder. The lens is surrounded by an annulus of packing material and is secured in position by a face plate which is attached to the housing, the face plate having a longitudinal annular flange which extends into the space between lens and housing and engages the packing. Opposed to the face plate flange and sepd. from it by the packing, is a compression ring longitudinally movable in the annular space surrounding the lens. The ring is engaged by screws mounted longitudinally in the housing, whereby pressure may be applied to the packing causing it to expand radially inward. The lens is maintained under radial compression, whereby a fluid-light seal is obtd. and the risk of lens blow out upon fracture is minimised. The packing is protected from attack by corrosive media.</p> |
