| 摘要 |
<p>An annular gasket for disc valves is fashioned by a method that consists in forming a continuous strip of sheet steel initially, so as to create at least one first longitudinal portion presenting a convex profile on one face of the strip, and at least one second longitudinal portion presenting a convex profile on the other face, then coiling the strip together with a wider graphite strip to produce a centreless flat spiral, and finally, pressing the flat faces of the spiral; viewed in radial section, the annular gasket (1) appears as a succession of alternating metal and graphite layers (8) arranged one alongside another in the radial direction and sandwiched between two flat layers (7) of harder graphite, obtained by the pressing operation, which provide two frontal sealing surfaces (6).</p> |
