Torispherical head calculations ASME VIII div. 1

[Chonwe]

Hello,
I am working on calculating a pressure vessel head using ASME VIII div. 1 code.
The torispherical head has the following dimensions: Do=1170, t=10, L=2100, r=50 (mm). The ratio t/L=0.004, which is greater than 0.002, so equations from UG-32 (d) shall be used. The main issue is that L/r=42, and L>Do, so it seems UG-32 can't be applied.
How can I overcome this? Is there any additional equation in the ASME code for this scenario?
Also, the head has stiffener rings from the center to the radial direction (6 in total), and I couldn't find a section that includes these rings in the head calculations. It seems that these rings were added due to the big L/r ratio.

Thanks for the help!

 

[IdanPV]

UG-32(d) shall be used for the case in which t/L≥0.002 and the knuckle radius is 6% of the inside crown radius and the inside crown radius is equal the outside diameter of the skirt, see UG-32(i).
Have you looked in Appendix 1, 1-4?
As for your second question, sounds like U-2(g) case for me.

 

[Chonwe]

In appendix 1,1-4 there is an equation for different knuckle radius and inside crown radius ratio, in terms of M. However, in the notes of table 1-4.2, says that L can’t be greater that the outside diameter.
It seems that U-2(g) should be applied, so I must make a FEA based on ASME VIII div2?

 

[IdanPV]

U-2(g) has 3 options:
1. Mandatory Appendix 46, which allows you to use FEA in accordance with App. 46-4 and VIII-2, Part 5.
2. Proof Test in accordance with UG-101.
3. Other recognized and generally accepted methods.

 

[DriveMeNuts]

The rings being added due to the big L/R, sort of tells you why the code doesn't accept this L/R.
The moment that you weld stiffeners to the crown of the head to enhance its maximum pressure, this the moment that this is no longer a head.
U-2(g) may be your only option.

 

[r6155]

Standard Designation:

BPV Section VIII Div 1

Edition/Addenda:

Para./Fig./Table No:

Subject Description:

Section VIII, Division 1 (2001 Edition, 2002 Addenda); UG-32(d) and Appendix 1, 1-4

Date Issued:

06/13/2003

Record Number:

BC03-619

Interpretation Number :

VIII-1-01-155

Question(s) and Reply(ies):


Question (1): When designing an ellipsoidal head with a head depth to diameter ratio different
than one-fourth, must the provisions of 1-4(c) be satisfied?

Reply (1): Yes.

Question (2): When designing a torispherical head with dimensions different than described by
either UG-32(d) or UG-32(e), must the provisions of 1-4(d) be satisfied?

Reply (2): Yes.

Regards