ASME VIII, Div 2 Conical Transition with Flare & Knuckle

[engpes]

Hi,
I am trying to determine the hoop and membrane stresses in a conical transition per ASME VIII, Div 2 section 4.3.12 and table 4.3.7.

I am having trouble specifying the variable Rf and Rk which are the radius to center of curvature for the flare and knuckle respectively. I have my rk and rk inside radius of knuckle and flare set to 11.5".

My question is:

1.) What exactly is the radius to center of curvature for the flare and knuckle (Rf and Rk)?
2.) How is this different from the inside knuckle and flare radius (rk and rf)?

This is a thick wall vessel 4.0" with a 28" OD. The alpha angle is 15 degree and my transition is 22" long. It does not apply for the part 4 no knuckle or flare ASME calculations and I cannot do the part 5 analysis per specific request from client. Thank you in advance.

 

[Geoff13]

Look at Figure 4.3.10. All four measurements are shown.

 

[engpes]

Exactly what I needed! I could not find the diagram anywhere. Thank you!