An isometric drawing is generally on a A3 size paper. To aid pipe fabricator on site, isometric drawings are prepared. But 3D scale model can not be put on a paper, and 3D scale model does not indicate dimensions. A pipe fabricator can understand GA drawing better only with the help of 3D scale model. A0 or A1 size drawing is to big to handle. A GA drawing is generally on A0 or A1 size paper and contains a lot of lines, and may not be easy to understand pipe routine. 2D General Arrangement (GA) drawings are used for fabrication on site. This is then converted into a 3D scale model, to check interference of pipe lines.
In this all pipelines are drawn at zero z co-ordinate. Why Isometric Drawings are required?: Generally in the development of a project, a conceptual 2D drawing is first created.
