COMPRESS increases the OD for wind load projected area as based on thickness of insulation. COMPRESS also separately determines the wind force acting on platforms and ladders. No increase in projected area is considered for nozzles or piping; the designer must enter a suitable value for "Increase Effective OD by" in the Wind Code dialog. Press the F1 keyboard function key when the Wind Code dialog is displayed, the COMPRESS Manual will open to the corresponding page with a description of this input.

Often, the owner's vessel specification will dictate what values to use for increase in effective diameter. A number of standard reference books for vessel design also indicate "good" values in order to account for nozzles and minor attachments to the vessel.

  Tom Barsh
  Codeware Technical Support

My understanding from several years ago, (possibly misunderstanding), was that only platforms were automatically included in wind load and ladders were not. Ladders are definetly now automatically included?

You're correct; thanks for the reminder and the "clearification". COMPRESS provides an option to automatically calculate the wind load on the platform or not (in which case the wind load should be addressed by increasing the effective OD). But this optional calculation does not treat the ladder, it treats only the platform.

The method used for this "automatic" check for the platform comes from the ASCE publication "Wind Loads and Anchor Bolt Design for Petrochemical Facilities".

  Tom Barsh
  Codeware Technical Support