The removal of tubes in bundle layout can happen due to several reasons:

1. Maintaining pass tolerance like we saw earlier this week the model that we worked on
2. To maintain height between tubes with impingement baffle
3. To maintain the TEMA inlet outlet condition requirement when ‘compute’ field in Bundle dialog box is checked to verify shell entrance and exit areas as per the TEMA calculations

If I remove the compute check option shown in above image

There is no vacant space in bundle layout:

See report section for this calculation when compute is checked and flow verification need to be performed: