There is no specific command in COMPRESS labelled "blast loading". However, you can specify a user-defined wind load under the Wind Codes to simulate the pressures produced by the blast load.
It has been years since I did any work with blast loads. As I remember, the dynamic force of the blast load is transformed into an equivalent quasi-static pressure (something like what is done for wind loads). Based on this you can specify the user-defined wind load in COMPRESS. COMPRESS will then calculate the total load acting on the horizontal vessel (in both lateral and longitudinal directions) and apply to the vessel and saddles.
Tom Barsh
Codeware Technical Support