Correct weight calculation method of anti-corrosion insulation steel pipe

In general, anti-corrosion insulation steel pipe is quoted by the price per meter, but there are many users require by the price per ton, at this time we must learn how to calculate the weight of anti-corrosion insulation steel pipe.
The weight calculation formula of anti-corrosion insulation steel pipe is the same as that of other pipes. (Diameter - wall thickness)* Wall thickness *0.024615
But many users say that the anti-corrosion insulation steel pipe is not on the basis of ordinary steel pipe to increase the anti-corrosion or insulation layer? The weight will definitely increase. How to calculate the weight without adding? Well, the manufacturers of anti-corrosion insulation steel pipes usually carry out hulo when converting the weight. Unless the weight must be calculated during the transportation process, it will be related to the freight, which is generally overweight.