[Nek5000-users] Wall flux contour plots in Visit

[nek5000-users at lists.mcs.anl.gov]

Howdy VisIt-eers among the Neks,

I'd like to visualize certain wall values (heat flux, say) in VisIt.
Is there a way to extract the boundaries from the complete nek domain in 
VisIt and then plot certain values only on them?
What might help with this is that I can create an identifier variable 
which would be 1, say, on all wall faces, 2 on all periodic, etc. (see 
post from Thu Feb 4.)

Thanks for any help,
Markus