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Hello, Everyone As per ASME SEC.VI 4

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Santosh Ingale

Mechanical
Feb 1, 2022
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Hello, Everyone
As per ASME SEC.VIII Div.2 I want help, how to calculate Axial force and Bending Moment of the flanges and bolting.If internal pressure 40 bar/4MPA is given by client.
Details with explanation will be appreciated
Thanks in advance.
 
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Santosh,

Try looking in ASME VIII appendix 2. Or search for this on this site as it has been discussed many times.

Axial and bending forces come from external forces to the pipe, not internal pressure ( though that has a component).

Do you mean you want to calculate allowable axial forces and bending moment on a standard ASME B16.5 flange??

What class of flange? Material?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Hello, Little
Yes, ASME B16.5 Class is #1500 & #300. Please find attachment drawing for clarity The message from clients end

Dear Santosh,


Please find below message from Client Engg Team.



Quote



To avoid any further delay, lets request vendor to perform the calculation for both flange body and bolt in accordance with ASME Sec VIII Div 2 using the following input data and advise on the following :

Maximum allowable Axial Force
Maximum allowable Bending Moment


Input data to be considered:

Internal Pressure – 4 MPa (40 barg as confirmed by you in the trailing email)
Temporary Flange Dimensions as per the attached drawing provided by the vendor


Once maximum allowable axial force and maximum allowable bending moment are available from the vendor, we can then send these loads to T&I engineering team to ensure that the loads during start up and lay down does not exceed these limits.



Let me know if something is not clear.
 
 https://files.engineering.com/getfile.aspx?folder=83099deb-4123-489f-ba95-1f2542d06ead&file=DRAWINGS_R1.PDF
It seems that both your client and you are dealing with a lack of understanding of the problem at hand.

Generally-speaking, the failure mode of interest when requesting the maximum external force and moment on a standard flange is with respect to leakage. That requires more than a simple calculation for your ring joint flanges (beyond that covered in ASME Section VIII, Division 2, Section 4.16.12). You would need to perform FEA in a similar manner as was done in PVP2013-97814. And there is a very tight interaction between the gasket selection, the assembly bolt load, the temperature (and extent of insulation), as well as any thermal transients.

You won't find your answer in ASME Section VIII, Division 1, Appendix 2, so don't bother going there, either.

You may need to call in an expert.
 
Is this for a flange on a pipe or a flange on a Pressure vessel?

If the former, a 30" class 1500 is very big. Being pedantic, these are ASME B 16.47 flanges, not 16.5.
"Start up and laydown" under pressure?

If it's a pressure vessel then the forces are not flange related, but vessel stress related and often very low.

As TGS4 says, these are not trivial calculations and really need to be looked at by FEA as the key is gasket stress to avoid leakage. I suspect you are looking for something which doesn't exist.

Also FEA and ASME VIII appx 2 calculations often shows "failure" of an ASME B 16.5 or 16.47 flanges at much lower pressure than the nominal P-T rating of the ASME B 16.5 and 16.47.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Thanks a lot, I'm very happy with your opinions.
I would like to express this is My first experience on this platform thanks a lot.
Dear Little & TGS4.
Thank you 😊
 
Isn't this the same question?

Your attachment won't load.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
TGS4 said:
It seems that both your client and you are dealing with a lack of understanding of the problem at hand.

Generally-speaking, the failure mode of interest when requesting the maximum external force and moment on a standard flange is with respect to leakage. That requires more than a simple calculation for your ring joint flanges (beyond that covered in ASME Section VIII, Division 2, Section 4.16.12). You would need to perform FEA in a similar manner as was done in PVP2013-97814. And there is a very tight interaction between the gasket selection, the assembly bolt load, the temperature (and extent of insulation), as well as any thermal transients.

You won't find your answer in ASME Section VIII, Division 1, Appendix 2, so don't bother going there, either.

You may need to call in an expert.

Same question - same answer. Same advice. You would be well advised to heed this advice.
 
Tried section 4.16.7 ?? Has axial force and bending moment.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
FEA it's an acronym which stands for Finite Element Analysis.

Please get some (professional) help with this. On the basis of your questions, you are in over your head. Get your employer to hire an expert in the field.
 
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