I got a Valve Part Drawing for 2" X 150#.
The designer put the Dimension for Flange as 13.9mm + 2mm = 15.9mm.
Whilst i asked him why he did so because the correct thickness shall be 14.3mm + 2mm RF = 16.3mm
But he did respond to me that designers usually did in this way : 14.3mm + 1.6mm =...