There is standard bolt hole connecting with the valve or bracket. The output axis in the middle is a standard internal octagon.

壳体上有标准的螺孔与阀门或支架相连。中间输出轴为一个标准的内八角。

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By the end of 1942 America's output of war materiel already exceeded the combined production of the three Axis powers, Germany, Italy and Japan.

ECONOMIST: The "dollar-a-year" men and what they achieved

To explain the graph a bit more clearly, the X axis is months and years, while the Y axis is the volume of industrial activity as a percentage of the average monthly output of 2009 (which, it should be noted, was depressed as a result of the global financial crisis).

FORBES: Russian Industrial Production Increases by 4% over 1st Quarter 2011