请教: in sizing and rating 怎么理解? 上下文如下: However, centrifugal pumps are used for low pressures (e.g., 100 psig) and multistage horizontal centrifugal pumps for high pressures (e.g., 700 psig) or high circulation rates (e.g., 300 gal/min). In sizing and rating pumps use a low positive suction pressure of 3 to 10 psig. 其它内容理解上都没什么问题,就是其中的 “In sizing and rating”搞不太明白,请各位指教,谢谢查看更多4个回答 . 1人已关注