泵的正常流量、最佳效率点流量、额定流量

API610的11版里面6.1.12额定流量点应位于所提供叶轮最佳效率点流量的80%-110%区间内；但是，6.1.13所提供的泵的最佳效率点最好位于额定流量点和正常流量之间。这两个是不是矛盾啊？如果额定流量在最佳效率点的90%，符合6.1.12的规定，但是不符合6.1.13的规定啊。

首先不矛盾，这里面说的推荐值而已，你看一下英文版原话，6.1.12 Pump shall have a preferred operating region of 70% to 120% of best efficiency flowrate of the pump as furnished.Rated flow shall be within the region of 80% to 110% of the best efficiency flowrate of the pump as furnished.6.1.13"the best efficiency point flowrate for the pump as furnished should preferably be between the rated ponit and the normal point"