ISO pipes are typically drawn using specialized software such as AViCAD which supports isometric drawings.
In this step-by-step walkthrough, we’ll set up your drawing for isometrics, activate the ISO grid, draw the pipe and fittings, create a BOM, and finally print/plot our ISO drawing.
Setting up the ISO drawing
In the configuration ribbon. You need to click on the scale. It should have DIMSCALE activated. DIMSCALE will allow our ISO annotations and ISO dimensions to scale properly based on our plot scale (more on that below).
We will set the units should be to English or Metric – select whatever scaling you need here.
DIMSCALE (AutoCAD command variable)
We need to set DIMSCALE factor and since we’re going to be working in half an inch this needs to be set for 24. See this scaling table for more.
This number correlates to how big the annotation or how small the annotations going to be in your pipe and iso drawing. Very important to determine your desired final plot scale (based on your paper size) and the appropriate scale factor or DIMSCALE.
DIMSCALE is a CAD variable that controls the scale factor for dimension objects. It determines the size of dimensions (and ISO fittings) relative to the real scale settings. It’s faster just to type the DIMSTYLE command in but you’ll also find in Dimstyles on the settings (see CAD command D for Dimstyles), It should also be noted that in Mech-Q, DIMSTYLE controls fitting, text and dimension sizes within Mech-Q.
Paperspace and viewports
Next. we need to start a new drawing and set the appropriate units (English or Metric) based on your project requirements. Define the drawing scale and sheet size.
Click on the start button. And where it says to use a template. We browse to select a drawing template. Once loaded you will see what we call Paperspace.
Within a Paperspace layout, we can define the scale, and various views (called viewports), and add annotations, dimensions, titleblocks, and borders. By switching between different layout tabs, we can select the proper paper size.
You’ll find three drawing sizes. We are going to be working on a 24 by 36 sheet.
Once the sheet to loaced Type MS for model space to activate the metal space viewport. Alternatively, you can also double-click on the viewport/
We need to set the zoom scale in the model space. You can set this to 1/24, which is our scale factor then XP. (1/24XP). You can also use the Annotative Scale list in the Status Bar and simply pull down the scale list there as well.
What exactly do we mean by scaling your drawing and viewports?
To understand AutoCAD scaling, you need to familiarize yourself with a few key concepts:
DIMSCALE: As discussed above, DIMSCALE is a system variable in CAD that determines the scale factor used for dimensioning. It controls the size of dimensions, text, and other annotation objects Adjusting DIMSCALE in Mech-Q also controls the size of fittings and welds in an ISO drawing.
Viewports: Viewports are windows into your paper space drawing that allow you to see different parts of your drawing at various scales. You can create multiple viewports to display different areas of your ISO piping drawing at different scales. Each viewport can have its own scale.
Zooming: Zooming allows you to adjust the magnification level of your drawing viewport. You can use the Zoom command to zoom into a viewport or better yet use the Annotative Scaling drop-down in the Status Bar.
Understanding these concepts will help you work with scaling in CAD and ensure that your drawings are accurately drawn at the desired scale.
Try the following to find our drawing limits:
Activate a viewport by dbl clicking on it. Draw a rectangle as big as possible to reach the extents of this viewport. (This is going to give us our drawing area or limits)
Now dbl click out of it to close the viewport. And then select the Model Tab to switch to model space.
Next, load the isometric utility and choose Settings.
Let’s make sure that the nodes are set to 0.03 so that they appear darkened. In our BOM options, we checked this unique item for each pipe.
Lastly, confirm the pipe lengths option is turned on. I recommend turning this on if you want those pipe lengths to show up on your BOM. And because an isometric pipe drawing is generally a sketch, those pipelines are going to be a lot shorter.
Creating an ISO pipe drawing
Here is an overview of the steps we need to take when creating ISO pipe drawings:
Draw the Piping Components: Select the appropriate pipes, fittings, valves, and other components in the Mech-Q dialog box. Common tools include straight pipe elbows and tees for example.
Activate the Isometric Grid: Within the main Mech-Q ISO dialog software, we can choose which grid we want to draw on. This grid allows us to draw and align the piping components in a 3D-like isometric perspective. Isometric grids follow a 30-degree and 60-degree axes.
Snapping: Enable snapping as we enter points, ensuring that your pipes and fittings connect to each other. This helps maintain the accuracy and proper alignment of the pipes and fittings.
Maintaining Consistent Scale: With the help of setting DIMSCALE (see above) Mech-Q keeps the size of our firrings consistent throughout the drawing. This includes sizes of fittings valves and welds – to ensure they are proportional to each other.
Adding Annotations: Mech-Q will also label the information about the piping system. This may include pipe sizes, lengths, and ratings.
Clean and Organize: Review your drawing to ensure it is easy to read and clear. Sometimes you may have to scale the schedule in order to make it fit on your drawing sheet.
Plot or Print: Once your ISO pipe drawing is complete, you can plot or print it to create a hard copy or save it as a PDF file for sharing.
So let’s activate the left ISO grid. Again, this is a sketch. So pipes can be any length. Remember Mech-Q is going to ask us for each pipe once it’s been imputed. As we turn pipe directions Mech-Q will also insert the elbow.
We’ll enter a series of points to define the pipe route. We’ll left-click once then enter a second point in the direction of pipe flow.
After we enter our third point we’ll be asked for the pipe length of our first pipe. So let’s just put in two feet here.
We’ll continue on to our fourth point.
Let’s put in two feet for the second pipe. Again we have to wait for the pipe to be drawn to enter this length.
And then press enter to complete the run – and we’ll put in two feet for the last pipe.
Next, let’s change the grid view using the dialog. We’ll erase the 3rd pipe and choose the top ISO view.
We’ll start from the fitting again snapping to the endpoint
And come down four feet and click there.
And three feet for next. Each time we enter the pipe length of the last pipe drawn.
Creating a Bill Of Materials (BOM)
So now that we have inputted our pipe, we are ready to run a bill of material on this. So let’s go back into the ISO utility.
Click the BOM settings.
And here I have the table building in a downward direction.
And then in my BOM options, I checked to itemize each pipe.
Let’s just start the bill of materials now. And create the BOM.
At each pipe we enter the starting point of the leader, With our Ortho or Polar snapping activated we’ll locate the arrow and click enter. We’ll do that for each section of the pipe.
Next, we’ll bubble the elbows in the same way as the pipe. If we need to skip a bubble, we can enter in the first point of the arrow then press S for Skip.
After we are done bubbling, we can insert our BOM table or schedule of fittings.
At this point, you’ll see that it’s tabulated all the lengths that we’ve established in the pipe and isometric drawing. We can scale down the table if needed using the SCALE command and setting it to .75 and then move it into our drawing sheet.
Plotting / Printing
Now if we go back into Paperspace I can see the layout here. You’ll notice the various colors in the drawing. But let me show you how we plot this to monochrome
Type PLOT and at the upper right, we set this to monochrome in our pen settings. We can plot this to paper of PDF if needed.
So hopefully this piping isometric tutorial has helped. Feel free to email us or call us if you have any questions
