Revit Mechanical Purging USED items in Model

[jordanheckman]

I have been using Revit for quite some time now and this is my first real issue that has arose that I have not been able to figure out. We are working on a fairly large health care facility where we are creating everything architecturally, mechanically and structurally in Revit. 

We have everything set up properly, architectural in one file, with mechanical and structural linked to that file. 

Our mechanical file was getting a bit overloaded with information so I had mechanical do a purge unused on the file. Everything seemed to have went fine until we noticed that all the plumbing risers had disappeared (yet the same family that was in a horizontal position had not been deleted). After some digging (using the back-up files) we had determined that Revit had indeed purged out that USED items in the file.

I am wondering if anyone else has had this issue?

Thanks!

[SteveKStafford]

I have not seen used items purged except in one situation.

If users are adding new work and another user runs Purge Unused and then uses synchronize with central BEFORE the other users adding new elements do, the previously unused elements that Purge Unused (the other user ran it) found are purged. When the other users then synchronize with central the work they did with those elements is deleted, not preserved or restored!!