For Guide, V-stop and Incline support types, when should Gaps setting = As-built or Weightless in an AutoPIPE model?
The As-Built option means the gaps are measured from an already built position. That means you went to the field and measured the gap below the pipe. In this case the existing pipe GR displacements are already applied, but no contact with the support. That means although DY > 0.002, no contact exist with the support. The local displacements show the support displacement which is zero since no contact. The global GR displacements DY show the pipe movement from the weightless position (or original undeflected position) which is non-zero.
Again, use "As-built" option when adding supports to an already existing piping system that after Gravity displacement has been applied then use defined gaps settings; otherwise use "Weightless".
See AutoPIPE help for complete details on this subject.
General FAQ's about Supports and Beams