In dimetric drawing, two of the three principal axes make equal angles with the image plane while in trimetric drawing, the three principal axes make different angles with the image plane. The three principal axes make equal angles with the image plane. It is created on the basis of parallel projection technique. Pictorial drawings are excellent starting point in visualization and design and are often used to supplement multiview drawings.Īn isometric drawing is one of three types of axonometric drawings. They show images that bear physical resemblance to the real or imagined object. They tend to present images of objects in a form that mimics what the human eye would The internal features of the object are largely hidden from view.

Pictorial drawings consist of visible object faces and the features lying on the faces. The principal dimensions are the overall sizes for the object along the three principal directions.

Pipe size – Given pipe size is 2″ and 1″.Isometric drawings are a type of pictorial drawings that show the three principal dimensions of an object in a single view.

Refering to the above Iso drawing, lets go through the item one by one: Let’s use the isometric below as an example An example of a pipe fabrication isometric drawing There are a few information that can be derived from an isometric drawing. Isometrics drawing is also the most important drawings for installation contractors during the field portion of the project.

It is often used by designers prior to a stress analysis and used by draftsmen to produce shop fabrication spool drawings. Piping isometrics are generally produced from orthographic drawings and essential to design and manufacturing phase of a very complex or large piping systems. Vertical pipe lengths are calculated using elevations, while horizontal lengths are calculated using north-south and east-west coordinates. Pipe lengths are measured using coordinates and elevations. Therefore, dimensions are required to specify exact lengths of piping runs. The isometric drawing is oriented on the grid relative to the north arrow found on plan drawings and not drawn to scale. Piping isometrics are usually drawn on a pre-printed paper, with lines of equilateral triangles form of 60°. Symbols like fittings, Valves and flanges are modified to adapt to the isometric grid. The Isometrics drawing are created from information found on a plan and elevation views. In a piping isometrics drawing, pipe is drawn according to it’s length, width and depth, and often shown in a single view.

How to read an isometric drawing