Class 150, 300 Forged flange marine pipe fittings

[micdunde]

Hello I have been trying to find specific standard design stress guidelines on marine forged flange fitting fabrications. I have berried myself in the following standards: AWS D1.1 2002 Structural Welding Code, Steel,
Welding Handbook 3rd Edition, ASME VIII 1992 BPV Code Division 1 & 2, AISC, ASME/ANSI B16.5 1988 Pipe Flanges & Flanged Fittings, API Spec 5L Specification for Line Pipe
API 1104. It seems that nothing in these standards refer specifically to fitting slip on weld (SOW), weld neck (WN) weld stress designs and sizing.

I just purchased AWS D1.1 2002 Structural Welding Code, Steel. Looking through this standard it appears to have lots of weld design and stress information + joint types etc however more geared towards hollow steel structural sections. Does anybody out there know of weld design stress guides/standards + joint types that can be traceable to the specific fabrication of marine 8-24" forged flange hose pipe fittings.

Or is it just that the guide lines of AWS D1.1 2002 Structural Welding Code, Steel are utilized for this application?


Regards

Phil

 

[MJCronin]

micdunde,

You are searching for " specific standard design stress guidelines".....I am not exactly sure what this means.

However, if you are interested in how ANSI B16.5 flanges are selected for power piping systems, look in ASME B31.1 or B31.3. These codes discuss how piping systems are sized for pressure and thermal conditions, and then flanges are selected.

Selection of ANSI B16.5 flanges comes after the piping diameter is selected and after the maximum pressure and temperatures are known. A table in B16.5 lists various flange "classes" and the maximum allowable T&P combinations for various materials.

Selection of qualified piping flanges is about all anyone does for most systems. There are calculations that can be made where the piping system encounters "external bending moments". These can occur under earthquake or wind loadings on the piping system.(See the Boiler & Pressure Vessel Forum on this website for more info on this topic)

Does this help ?

My thoughts only...


MJC

 

[micdunde]

Thank you for the info. More specifically I am interested in the standard code that defines and describes the allowable weld stress design calculations for the welds for SOW, WN 150 and 300 class forged flanged fittings.

Regards