Doing this to apply load on an orphan mesh. The meshing software (scanIP) I'm using is able to export the faces at the extreme of each axis (X, Y and Z). I need to convert one of them into a surface to be able to apply a pressure load.
best is to do it from CAD or selecting the surface based on angle go to replay file and put it in your script. But it is round about way. Also depends on what type of surface you use. If its planar you can use bounding box to select surface. hope it helps.