Rectangular Flanges Calculation

[kodzak1981]

Hi,

I need to calculate an air coolers headers acc. to ASME. I'm using appendix 13 for boxes, but I need to calculate rectangular bolted cover. I have found one thread here posted in 2002 saying that I should use UG-34 and bolt load to calculate acc. APP-2 (for circular flanges).

My question is how to determine G (gasket reaction factor) which is included in formulas for "W"... when my gasket is non circular?

And other thing, is this method using APP-13 for boxes correct?

Thanks in advance

 

[heatexguy]

The Code has no design for rectangular flanges. U-2(g). I use "Design of Process Equipment" by Kanti K. Mahajan to design box header flanges. Appendix 13 is correct for box design.

 

[kodzak1981]

Ok, thank you for your reply and help. Can you tell me is that method acceptable and correct for inspectors and other approval authorities?

Thanks

 

[heatexguy]

It would be up to your AI to accept, I can't see why he wouldn't.

 

[jamesl]

The other reference for rectangular flanges is the British Standard PD5500.

 

[Crompto29]

As Jamesl says, PD 5500 Enquiry Case 133 has a procedure for recangular flanges.

 

[kodzak1981]

@heatexguy,

After I have found that book, I saw the calculation and that is it.

Thanks a lot to all.

Cheers

 

[EngAddict]

If you understand what the formula for circular flanges are doing you can substitute the perimeter and area for rectangular flanges and use the same equations. That is all that is in PD5500 or the books.

Be careful when calculating the stress in the bolts for the operating case as unlike circular flanges the bolt loading is not uniform and the bolts in the middle will experience a greater reaction. You should always check the reactions with FEA, many people get caught out by this.