EN 13445-3 - Design of flanges (ch.11)
This sheet may be used for both design and verification purposes. For the design stage you should set only the data in blue. After doing so, data in green, such as number of bolts or flange thickness, will contain minimum values corresponding to the design criteria. At that point you should set data in green to your design values to get the final verification
Please note that a suitable design may not be defined for any set of data, and particularly for any bolt size. If you don't get satisfactory results, try increasing the bolt size
Allowable stresses
If the material table chosen for a specific part, as shown in the field 'Standard', contains the required values (yield and/or tensile stress depending on actual material) the allowable stresses are automatically calculated according to EN 13445 rules. Otherwise you get a zero value and you will have to set it manually.
Warning: not any material standard is allowed by EN 13445: check this with the code.