UG-44 and flange external loads 7

[OnG_Engr]

All,

I've been addressing the changes in UG-44 regarding flange external loads by designing said flanges to Appendix 2. It has been strongly suggested that instead we just put in the quote and on the drawings, in large font, that the flanges are designed for zero external loads and it is the Customer's responsibility to brace their piping. Since UG-44(b) says "External loads MAY be evaluated..." instead of "SHALL be evaluated", I can't see a Code reason why we can't call out zero end loads and put it on the Customer.

Is just putting zero flange loads in the quote and on the drawing sufficient? Something doesn't feel right...

 

[SnTMan]

OnG_Engr, briefly:

1) I can't make sense of the thought that if one flange of a given type in a pair is not sufficient for the imposed loading that the other one would be sufficient.

2) I can only interpret this as PR is enough greater than PD that Eqn 1), CC2901 is satisfied. I assume to show this relies on the Apx 2 MAWP calclations.

I hope you can get TGS4's Inspector to buy in

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[oknow]

TSGS4

UG-44 states (b)(3)The bolt material shall have an allowable stress equal to or greater than SA-193 B8 Cl. 2 at the specified
bolt size and temperature.

If applied or even greater stress from a different Bolting Material, "How is this conveyed to the end user"? How will they know what bolting to be used? The suggestion is to add a note in UG-44 to indicate the Bolting Material and size in the Remarks Section of the ASME MDR. This could be added to the Appendix W Guide for Completing the ASME MDR's however it is often overlooked.

Not clear on how often Appendix KK "GUIDE FOR PREPARING USER’S DESIGN REQUIREMENTS" is used but it should be. A field should be added for "External Loads on Welding Neck Flanges"

 

[SnTMan]

In that spirit, the Eqn 1), CC2901 relies on a known value of "G" for the given flange. So the type (dimensions) of that gasket must be known. Somebody kind of needs to specify that as well.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[TGS4]

oknow and SnTMan - thank you for your feedback. Excellent suggestions.