Problem:

How to model a Stub End, Swivel, or Misalignment Flange in AutoPIPE ?

Solution:

The swivel flange is used with medium service pressures at points where the bolt holes in the mounting flanges are not precisely aligned. The swivel flange simplifies fitting between 2 fixed points.

For stress analysis purpose, the program needs to know the weight and SIF associated with a flange. Most ASME piping codes do not have established SIF values for these types of flanges. Whilst ASME 16.5 and 16.47 codes are applicable for weld neck flanges, they are not applicable to swivel ring flanges beyond the bolt pattern and bolt sizes. ASME offer alternative rules that consider swivel ring flanges as non-standard, or loose type, flanges.

Use the following modeling approach for these types of flanges:

Select the node point where the flange is to be located, press Insert> Flange>, on the flange dialog screen enter:

• Flange type = NS
• Pressure Rating = NS
• Weight = Enter weight  (see from vendor literature)
• Joint End Type: User Defined
• Joint SIF: Enter SIF value (contact flange manufacture for value to be used.)

Note: One could argue to set Joint end type = "Lap joint" in order to automatically calculate the SIF. However, since these types of joints are not covered by the applicable piping code, you will need to use engineering judgement or contact the manufacture. Bentley TSG cannot provide a definitive values.

See Also

Flange Piping Components - Modeling Approaches, Tips, Techniques

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

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