| 摘要 |
<p>The flange is used to join end-to-end two sections (13,14) of the outer casing of the cable duct, and has a radial passage connecting the interior of the duct to the outer edge of the flange. The outer part (30A) of the flange is enlarged to accommodate a gas control valve in the radial passage. The valve has two seats (S1,S2), and can be operated from the outside to provide various communication paths for the insulating gas. The two duct sections can be put in communication with or isolated from each other, the two duct sections can be in communication with the exterior, or one of the pipe sections can be in communication with the exterior while the other section is isolated. The external access point on the edge of the flange is closed by a cover (50) with a screw-in plug (52) to connect gas lines.</p> |
