covers as welded box construction with horizontal top-plate and double drain

题目

covers as welded box construction with horizontal top-plate and double drain
Covers as welded box construction with horizontal top-plate and double drainage system.
请问怎么翻译
covers as ...在这里是什么成分

答案

welded box construction with horizontal top-plate and double drain
带有水平面板和双排水系统的焊接好的箱状结构