Torispherical Dishend Thickness Calculation Problem

Vessel ID: 2100 mm

Length (T/T): 3900 mm

Thickness: 6 mm (considered)

Vessel Type: Horizontal Cylindrical with Torispherical Dish End

My Self Calculate,

Inside Crown Radius of the Torispherical is ( L ): 2112 (OD of the Vessel) &

Inside Knuckle Radius is ( r ) 126.72 (6% of Inside Crown Radius),

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So I calculate as per ASME Sec VIII Div – 1 UG 32 (e)

The condition is ts/L ≥ 0.002 is satisfied

And the formula for the thickness calculation is tp = 0.885 P L / S E − 0.1P

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But as per ASME Sec VIII Div – 1 Appendix – (1- 4)

The same condition is ts/L ≥ 0.002

The L/r ratio is involves ……….

L /r ratio is inside crown radius to the inside knuckle radius, used in Table 1-4.2

Thickness formula is

t p = P L M / 2 S E − 0.2 P

and L/r = above 16 means M factor calculate separately…..for another formula in App 1-4

In my case the L/r is 16.6 and I have to calculate the M factor value separately and thickness calculation

is achieved as per ASME sec VIII div – 1, App 1-4

Thickness formula is

t p = P L M / 2 S E − 0.2 P

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Here my questions are,

1. Is it wrong for using this condition (L/r is 16.6) as per ASME sec VIII div -1 UG -32 (e) thicknesses formula is tp = 0.885 P L / S E − 0.1P.

Why because I already consider the inside knuckle radius is 6% inside crown radius as per the code.

2. If L/r = 16 means, which formula I have to use?

3. If L/r <16 means, which formula I have to use?

4. If L/r > 16 means, which formula I have to use?

5. As per UG -32(e) and App 1-4, when I go for these L/r ratio?

Please help me in this query and am expecting your comments with references please …..