Use of SAE Code 62 Flanges on ASME Section VIII Div 1 pressure vessels.....

[JulianNesbitt]

thread292-30766

Does anyone do this? How was it qualified? Was it qualified as an Appendix 2 flange?

thanks,
Jay Nesbitt

 

[TGS4]

You wouldn't be able to qualify these using Appendix 2 - the geometry just wouldn't work. You'd be stuck using U-2(g), and depending on the jurisdiction, that may be a tough sell.

 

[JulianNesbitt]

Thanks for the quick response! We are reserving the use of U-2(g) for the present.

Would you please expand on your comment of the geometery not being consistient with A2?

2-1 SCOPE
(a) The rules in Appendix 2 apply specifically to the
design of bolted flange connections with gaskets that are
entirely within the circle enclosed by the bolt holes and
with no contact outside this circle, and are to be used in
conjunction with the applicable requirements in Subsections
A, B, and C of this Division.


and

These rules provide only for hydrostatic end loads and
gasket seating. The flange design methods outlined in 2-4
through 2-8 are applicable to circular flanges under internal
pressure. Modifications of these methods are outlined in
2-9 and 2-10 for the design of split and noncircular flanges.


So, I am not understanding the geometry limitations, although I am relatively unfamiliar with A2.

thanks,
Jay

 

[TGS4]

Based on the pictures that my google search found for these flanges, I daresay that they are not necessarily circular. Correct me if I am wrong, but the bolts are at 11-o'clock / 1-o'clock and 5-o'clock / 7-o'clock and the flange ring outside the circular contact area is not circular, but rather obround. It is true that you could apply 2-10, but I think that you may have a difficult time complying with 2-5(d), equation (3) and 2-6, equation (7). The spacing between the bolts on the two sides may be too big for the equations.

If it were me, I would argue that the geometry doesn't fit in Appendix 2 and would apply U-2(g).

 

[JulianNesbitt]

Non- circular flanges are OK. This was what I thought you meant, so I quoted A2.

This flange is rectangular, not obround (but we have definately done obround flanges).

The thing is that the self-energizing gasket (O ring) does not require significant bolt load to work (M=0; Y=0), therefore bolts only carry pressure load. IE: number of bolts req'd decreases.

I was out friday. Our A2 expert was checking on this Fri, but he comes in at 8:00. I'll see what he found.

Thanks for your more detailed comments.


Jay

 

[JulianNesbitt]

Due to the non-listing of 1020 steel and the lack of desire to manufacture it from approved material, we have relegated the usage of these flanges to B31 applications.

thanks for the help.

Jay