ASME Section VIII Appendix Y

[nuche1973]

Greetings all:
Can any one clarify the definition of Ab in appendix y? I am calculating the stresses in a loose flange (Class 1 Category 2 type flange). My vessel is operating at 14.5 psi (304L) material. My hang up is the Operating Bolt stress (eqn 11) is extremely high (230 ksi) for a 1/2" SA-196 bolt (24 total on a 60" bolt circle diameter). This also affects my Design Prestress in the bolts. Ab is defined as the "cross sectional area of the BOLTS using the root diameter of the thread or least diameter of unthreaded portion, if less". Does this translate to: Area of bolt x number?

 

[SnTMan]

Ab, total cross sectional area, see Y-4(b).

24 1/2 bolts on a 60" circle? Seriously?

Regards,

Mike

 

[trottiey]

Yes. Ab is the total root area of all your bolts put together.

 

[nuche1973]

thanks for the information. I appreicate it.

 

[TJOrlowski]

Good luck getting that gasket to seat properly.

-TJ Orlowski