知识贝壳
知识贝壳
所属栏目：水轮机与水泵专业英语
There are many variations in the design of the screw type positive displacement, rotarypump. The primary differences consist of the number of intermeshing screws involved, thepitch of the screws, and the general direction of fluid flow. Two common designs ......（本文共 2849 字 , 2 张图） [阅读本文] >>