cylindrical grabhead是什么意思

用法例句

The formula which ascertain the coordinates center of the circle of the manhole skirt transitional circular arc of boiler drum ellipsoidal head has been deduced,which can be a reference when it is drawn by computer.

推导出确定锅炉锅筒椭圆形封头人孔板边过渡圆心坐标的公式,可供计算机绘图时的参考。