An interference check is marked as out of date 
when any pipe network part in the interference check is changed. Even changing a description on a pipe network part that is not in interference causes an interference check to become out of date. So does moving, deleting, or adding parts to any network included in the interference check.
- In Toolspace, on the Prospector tab, expand the Pipe Networks
Interference Checks collection. - Right-click the interference check and click Rerun Interference Check.
The following prompt is displayed:
Interference check created.
Number of interferences found: X
- Click OK.