Problem

Is it possible to have the constraint based design feature design a conduit's inverts but not the size? Can I "set" the pipe diameter and have the program design only the inverts?

Solution

Currently (as of 10.01.00.70) it is not possible for the program to automatically design the inverts but not the size. This has been logged as a feature request for future consideration.

The typical use case, which the program was designed for, is the design of a proposed system where both the sizes and the inverts are designed. Keeping the sizes the same would indicate that you may be redesigning an existing system using the existing conduits, but possibly burying them at a different depth. This is a bit of an atypical case, hence the need for a workaround.  

Here's what you can do to workaround this issue:

1) Open your conduit flextable and add the label column along with the diameter column and place them next to each other.

2) Sort your conduit table by ascending labels by right clicking on the label column header and choosing Sort > Sort Ascending.

4) Highlight all the records for the label and diameter columns and hit the CTRL + C to copy them

5) Open a new Excel spreadsheet and paste the information in.

6) In the conduit flextable add the conduit type, conduit class, and size fields if they're not already available.

7) Global edit the conduit type from "User Defined" to "Catalog Conduit". You do this by right clicking on the conduit type column header and choosing global edit.

8) Open the conduit catalog (Components > Conduit Catalog) and add in some conduit shapes and make a few sizes available for design by checking the box labeled "Available for design?". If you want you can just import some from the engineering library by clicking on the drop down arrow next to the book icon and choosing import from library.

9) In the conduit flextable right click on the conduit class field and choose to global edit it. Choose one of the shapes. Now right click on the size field to global edit that then choose one size for all the conduits.

10) Run the software in design mode to update all your inverts.

11) Open your conduit flextable and global edit the conduit type field to "user defined". Make sure all your conduits are still sorted by label in ascending order.

12) Copy the diameter information from the Excel spreadsheet and paste it back to the diameter field in the flextable.

13) Re-compute the model. 

Alternative Workaround

If your conduit sizes are all the same, consider temporarily unchecking all the "available for design" boxes for all the other diameters, in the respective Catalog Class (in the Conduit Catalog), calculate a design run, then re-check the boxes (for future design runs.)

See Also

Is there any way to only adjust the pipe size without changing the invert?