Flange Design 42" Class 1500 #

Hello,

as per asme VIII - Div-1, Table U-3, the list of codes are mentioned, which you can refer & use in the designing of vessel as per ASME VIII- Div,1

B31.3 is not mentioned in the table, hence I afraid, vendor need to follow ASME VIII Div-1 approved material, so either ref, material/ Design as per Table U-3 or Follow ASME II-A/D

I hope this is sufficient for you.

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INCORRECT - see comment #2 below.

What type of system will this design flange be ultimately installed in?

If you are designing a flange for B31.3 piping then use the B31.3 allowables as per:

B31.3 304.5.1

"(b) A flange may be designed in accordance with the
BPV Code, Section VIII, Division 1, Appendix 2, using
the allowable stresses and temperature limits of the B31.3
Code. Nomenclature shall be as defined in Appendix 2,

except as follows: ..."

If you are designing a flange to be installed on a Section VIII VESSEL use the Sec II allowables.

Thanks Guest.....This is what i was looking for....yes, i am connecting my flange to valve in line with piping code only..so i will be using allowable stress of B31.3 only.

WOW.... 42 inch and 1500 class !!

What is the design temeperature and pressure of the system ?

Its in Offshore application....3000 psig and 200 Deg F..

All design calculations for flange shall be in accordance with ASME BPVC, Section VIII, Division 1, Appendix 2. And all allowable stresses shall be obtained from ASME BPVC, Section II, Part D (Table 1A , SubPart 1). The TEMA code itself ask to fellow the rules of ASME VIII, Div. 1 while you proceed a design for any flange required for a heat exchanger.

Also, the acceptance criteria for stresses (ratio of actual to calculated in both operating and seating conditions) such as S_H, S_R, S_T, 0.5(S_H+S_R)... etc. shall be governed and controlled by the rules of ASME VIII, Div. 1, Appendix 2-7 and 2-8.

See the attached example of flange design calculations: Flange_Design_Calculations.

Acceptance limit of stress is that comparison of the actual stress (calculated) and the allowable stress (acceptance criteria) as indicated per the code.

@ Galala,

Thanks for the detailed reply but as far as allowable stress values are concerned, i still agree with the post commented above about B31.3 304.5.1 since flange is to be connceted to valve only and not to mechanical equipment like heat exchanger. Had it been connected to mechanical equipment, i would have considered the allowable stress values from Sec II part D only.

Yes, I agree you and Guest (Post #2) where Para. 304.5.1 of ASME B31.3, allows using of its allowable stresses of Table A-1 in design of flanges.

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