You would model the spiders as restrains on core pipe with CNode to the jacket.
Assuming the pipe runs in X-directions, the most probable restrains would be Y (vertical) and Z (lateral). If the actual spiders are "rotated" or the spider legs are not normal to each other, then you can introduce a restraint with direction cosines. Let say, the spider (with 4 perpendicular legs) is rotated 45degrees in "torsion" plane, then restrains would be Y(0,1,1) and Y(0,-1,1). If the actual spider legs are with a specific angle, then again, use the direction cosines based on the drawings geometry...
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Nadia Strikovski
Intergraph CAS