请翻译工厂有8个一级成品油灌其中两个罐容是7500吨6个是3000吨。另有一个约3000吨的三级油灌。成品油在进入成品油灌前经流量计被计量。

There are 8 primary finished oil tanks in the factory, including two tanks with a capacity of 7500 tons and six tanks with a capacity of 3000 tons. There is also a tertiary oil tank with a capacity of approximately 3000 tons. The finished oil is measured by a flow meter before entering the primary finished oil tanks.