| 摘要 |
<p>A dish for securing to a conduit, the dish comprising a base plate securable to the conduit and a plurality of blades pivotally attached to the base plate. An elongate edge of a first blade is lockable to an elongate edge of an adjacent second blade. Also a method of urging a conduit. Also a conduit for the transportation of a fluid, the conduit comprising an outer surface and a plurality of fins on the outer surface of the conduit, each fin having a concave and a convex surface. The plurality of fins extending in a helix around the outer surface of the conduit.</p> |
