01. Flange Optimization methods in AutoPIPE Vessel


Applied to Taylor Forge Method (ASME, PD5500, CODAP, EN13445-3 part 9)
Four methods are available:
Only where Vessel Properties "Design" option is chosen, then flange optimization options are used by the program to either locate the gasket close to the bolt circle or to calculate a forging with a thin and long hub.
 

Option 1 (Short Hub and optimization of the Gasket Circle Reaction)

Option 2 (Hub stress and Gasket Circle r action optimized)

Option 3 (Short hub and Gasket close of the bolt circle)

Option 4 (Hub Stress optimized and Gasket close of the Bolt Circle)

Summary

 
Options 1 and 3 give a small hub and consequently a greatest thickness of flange, the difference between these 2 options is the location of the gasket and that has, as consequence to have a different number of bolts.
Options 2 and 4 give larger hub to optain a smaller thickness of flange, the difference between these 2 options is the location of the gasket and that has, as consequence to have a different number of bolts.
The choice of the option must be considered case by case and may give more differences regarding the design conditions and final gasket size and type selected.
To minimize lathe turning with short hub then best method is a Option 1 but is not best for equilibrium. If forged flanges are preferred then Options 2 & 4 are best to minimize the stress in the hub and preferrably using flange factor, f = 1.