| 摘要 |
<p>Metallic tube, pipe and conduit are made in a continuous process that includes a zinc galvanization stage, a first passivation stage, a second passivation stage and a third passivation stage. A colorant is added to the tube, pipe or conduit during the continuous manufacturing process, and the colorant imparts the appearance of a color, such as red. The continuous movement of the tube, pipe or conduit is not halted during normal operation of the tube, pipe or conduit manufacturing and coloring process.</p> |
