Flange Thickness and Steel Plates

YES. ASME VIII DIV 1 Appendix 2 is applicable for this flange. Give me your details of problem. I will help you.

• Per ASME code, it is recommended to fabricate any flange from a forged material, but sometimes we proceed a designs depend on a flanges fabricated from a plate.

• See the attached file in PDF format for detailed design calculations of nonstandard integral flange as per ASME code VIII, Div.1, Appendix 2: Flange_Design_Calculations.

• Also the attached file in PDF format for design of blind flange per ASME code, VIII, Div.1, UG-34: Blind_Flange_Design_Calculations.

• See CR4 Thread : Calculating Flange Thickness

Thank you for your comment. The problem I am facing is that I have to use plate < 1" thick. I have tried to use gasket with low "m" factor and small size of bolts, but it cannot lower the flange momment Mo to get the allowable stress seating of tangential flange less than the allowable stress of the flange material SA-182 F316L ( 16,700 psi ). What is the other factors that can reduce this allowable stress? Your comment is appreciated.

• " ..... to get the allowable stress seating of tangential flange less than the allowable stress of the flange material...."

No way to nominate that by allowable stress, so it is actual calculated stress located in the flange due to loading condition, and this calculated stress is required to be compared with the allowable tangential flange stress.

• From ASME code VIII, Div. 1, Appendix 2-7(a), and by referring to equation (8) used for calculating the actual flange tangential stress: S_T = (Y Mo / t² B) - Z SR, you will find that the most effective way to reduce S_T (for both cases: operating & seating conditions) is to increase the flange thickness, t.

You are right, I have to increase the flange thickness, even after I use gasket with low m and Y factor. My latest calculation shows that I have to use at least 1 3/8" plate thickness instead of 1".

Thank you for your comment.

My dear Gunarso Sudoro,

You are welcome in forum of professionals CR4.

If your pressure is low and/or vacuum, try a full face gasket with a gasket that has low m and y values.

I have choosed a gasket with m= 2 and Y = 1600, and the result is that 1" plate is not suitable for the flange, the minimum thickness which meet the requirement is 1 3/8". Therefore, I think there is no other option unless replacing the 1" plate with 1 3/8". Your comment is appreciated.