According to the approximation of the velocity profile of turbulent flow in cylindrical pipes, flow rate measurement based upon the maximum velocity of circular cross-section is proposed.

The former is used for liquid spraying in thick pipes to ensure against gas short-cut and the latter is particularly fit into the pipes with large flux and high velocity of gases passing through.

In this article, the dumping machine for centrifugal casting iron pipes was analyzed, the profile equation of constant velocity board was deduced, and the shape of the board was thus computed out.