| 摘要 |
<p>The valve is constructed in a rigid elastomer or plastics material and consists of an outer casing (9) which is fixed to the inside of the reservoir wall (2) by pins (10). The reservoir drain pipe (3) terminates at and is welded to the valve casing so that its extreme inner end forms the seating for the valve wedge (4). The valve wedge runs loosely in a vertical guide (15) and consists of a back-plate (6) with a lining (5) on the vertical sealing face. To the upstream face of the wedge are fixed tapered ribs (7) which mate, in the closed position, with a corresponding inner surface (8) so that when the valve is screwed down, by the spindle (11) a watertight seal is obtained.</p> |
