This is as I always say, easy if you know how.
Plant 3D has a lot of spec lines by default though a lot of companies are not very interested in detailing the material,
Some, go as far as just stating Mild Steel or Stainless 304/316.
If we look the picture below, you can see the line is using a default 16HC01 Spec.
Let’s add a Spec called MS for Mild Steel.
Open the Project Settings,
Navigate to Pipe Line Segments under P&ID DWG Settings > P&ID Class Definitions >
In the Properties, Select Spec,
Then click the Edit button.
The Selection List Property window opens,
as we can see, the current Specs and their descriptions, that are currently in the project, in the Value and Description columns.
Click the Add Row button to add a new Spec.
In the Value field, insert MS, this is what will be displayed on the line.
In the Description Field, insert Mild Steel, this is so others know what MS stands for.
Click the OK button.
The new Material Spec has been created,
If you want to get rid of unwanted specs, just select the value row and select the Delete Row button.
When you are done,
Click the OK button.
Back in the Project Setup window,
Select the OK button to accept and apply the changes.
Go back to a line and open its tag.
Expand the Spec dropdown, then find and select your new Spec.
Select the Assign button.
The line tag should update to display the new spec.
