Seismic freeboard and Design Liquid Level 1

[rab1944]

Must the Seismic freeboard in SUGII and III designs need to be added to the design liquid level. EC.3.1 states that these groups "indirectly influences the performance level expected of the tank." I feel that this is probably not necessary and is already accounted for since E.7.2 speaks of the "height of the sloshing wave above the product design height.........".

 

[JStephen]

The design depth used for shell thickness can be the top of the shell, some arbitary product level, or an overflow level. If an arbitrary level or overflow level, you would not add the freeboard when calculating shell thickness, if that's what you mean. (The additional pressure due to sloshing into the freeboard would actually be included in the convective sloshing term in the seismic hoop stress equations.)