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No vertical seismic force applied to lug

No vertical seismic force applied to lug

No vertical seismic force applied to lug

I am using the "User" Seismic inputs to apply horizontal & vertical accelerations to a vertical pressure vessel supported with 4 lugs.  I have input both vertical and horizontal accelerations, but in looking at the lug calculation report, it does not appear that the additional force from the vertical acceleration is being accounted for.  I can see that it appears in the shell analysis.

Any ideas on what is going on?  Am I missing something fundamental (setting or some such) or is it simply not done in COMPRESS?

In addition, on the seismic report, I notice that the vessel height stated is much less than my actual vessel length (4.5ft vs. an actual vessel length of about 13 ft).  The lug supports are about 1/3 the way down the vessel from the top body flange.  It appears to me that the height stated is only the vessel portion above the lug supports.  Is this true?  If so, why is there no account for the rest of the vessel below the lug supports (or am I again missing something fundamental)?

Thanks for any insight.

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