Pipe length is curved in the direction with figures showing the curvature of the curve. Standards set forth in the curvature is generally divided into the following two categories:
A, local curvature: by one meter long ruler in the maximum bending of steel tubes, and measure the chord height (mm), which is the local curvature value, the unit for mm/m, methods such as 2.5mm/m. This method applies also to the tube end bending.
B, length of total bends: with a piece of string, from both ends of the tube tension measuring pipe bends maximum chord height (mm), and then converted to length (metre) percentage is pipe length length in the direction of curvature.
For example: pipe length is 8M, 30mm maximum chord height measured, it tube full length bending should be: