Siemens COMOS Operating Manual page 147

Bolt length calculation for the normal bolted connection
Example: Two flanges with gasket and normal bolted connection
BL = Bolt length
The bolt length is calculated as follows:
1. The clamping length is calculated.
2. The bolt parameters are determined.
3. The theoretical bolt length is calculated.
Calculation of the clamping length
The clamping length is determined from the 3D model on the basis of topology.
Formula: Clamping length = Sheet thickness + gasket height + sheet thickness
● Gasket height: Is read out from the properties of the gasket, "3D geometry" tab, "Length
(L)" attribute.
● Sheet thickness: Is read out from the properties of the flange, "Connector <counter>" tab,
"Sheet height" attribute.
If the attribute is missing or blank, the internal calculation formula is used to determine
which basic table the sheet thickness is read out from.
PipeSpec Designer
Operating Manual, 09/2014, A5E32076948-AA
13.2 Algorithm for calculating the screw length
Database reference
147