WRC 107 vs WRC 297

can u plz tell me wht is the basic difference b\w WRC 107 and WRC 297

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WRC 297, Paragraph 1.0:

"This Bulletin is a Supplement to Welding Research Council (WRC) Bulletin 107 and is specifically applicable to cylindrical nozzles in cylindrical vessels. As such, stresses in the nozzle at the juncture with the vessel that were not covered by WRC Bulletin 107 can be calculated."

It doesn't get much plainer than that. WRC 107 focuses on the local stresses in the vessel. WRC 297 extends this to consider stresses in the nozzle.

WRC also extends the D/T and d/D ranges and considers the effects of the nozzle neck thickness.

none of the links in the posts work!
Please do something about it!

Richard Ay,

In pipe Stress analysis, nozzle load are exceed the allowable in that case we have to check the WRC 107/297. i give a actual load to vendor for calculating WRC 107/297 requirements. we also do the same load internally.

Actual nominal thickness of vessel is 12.7mm material is SA 106 gr.b. but vendor considered the vessel thickness as 11.1125mm. Hence the WRC 107/297 fails. if we considered 12.7mm all load are within limit.

client response:

For the pipe where listed in table 2 of ANSI/ASME B36.10, shall consider the reduction 12.5% of mill tolerance. In this case, when the nominal is 12.7 mm wall thk of pipe or cap, so the minimum/actual thk that we have to stated in mechanical calculation will be 12.7-12.5% = 11.1125 mm.

My question, plate thk shall be 12.7mm why they did 11.1125mm for Negative mill tolerance. pls guide me

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Please find the following noteworthy differences between the two:

• WRC-107, entitled “Local Stresses in Spherical and Cylindrical Shells due to External Loadings”, was released in 1965 and updated in 1979. WRC-297 was released in 1984 and goes under the title of “Local Stresses in Cylindrical Shells due to External Loadings –Supplement to WRC Bulletin No. 107”
• Both deal with “local” stress states in the vicinity of an attachment to a vessel or pipe. As indicated by their titles, WRC-107 can be used for attachments to both spherical and cylindrical shells while WRC-297 only addresses cylinder to cylinder connections. While both bulletins
are used for nozzle connection. WRC-107 is based on un-penetrated shell, while WRC-297 assumes a circular opening in vessel. Both bulletins assume that the nozzle (or attachment) axis is normal to the vessel. Furthermore, WRC-107 defines values for solid and hollow attachments of either round and rectangular shape for spherical shells but drops the solid/hollow distinction for attachments to cylindrical shells. WRC-297, on the other hand, is intended only for cylindrical nozzles attached to cylindrical shells.
• The cook-book approach found in WRC-107 resulted from the analytical work of Prof. P. P. Bijlaard and assume a shallow shell theory for spherical shells and flexible loading surfaces for cylindrical vessels. Therefore, WRC-107 requires that the Dm/T ratio be greater than 50 and
limits the d/D ratio to below 0.3.
• WRC-297 can be applied to a larger d/D ratio (up to 0.5) since the analysis is based on a different, thin shell theory (derived and developed by Prof. C. R. Steele).
• WRC-107 only computes the stress states of the vessel/header shell while WRC-297 also provides stress states for the nozzle/branch connection. WRC-297 also provides calculations for nozzle/branch flexibilities.
• Neither bulletin considers shell reinforcement nor do they address stress due to pressure.

SJ

Keep Smiling...It always helps!!!

I am dealing with a nozzle which comes out of the lower dish end of a vertical vessel at an angle, then straightens to come out of the skirt of the vessel. Now this nozzle is the lower outlet point for a level gauge. New valves have been added on the pipes before level gauge flanges on upper and lower part. I need to check if nozzle is safe.
Now question is can I use WRC 107 to check this nozzle?
If not then how to check the nozzle's integrity?

Probably I could not phrase my question properly.
So I am attaching a sketch for the nozzle.

Can we use WRC 297 for dish end nozzle.
Awaiting your reply.

SAM.

WRC-107/297 are for cylinder-cylinder intersections.

Richard,

Without wrc equipment model i used anchor and cnode on nozzle neck. is there mention in caesar manual. i searched in caesar help but i cant find this.
normally my practice is anchor and cnode on nozzle neck but my boss is saying this is wrong can u help me urgent basis.
awaiting your reply.
sma

WRC is not going to help you here with the flexibilities or the local stresses. As I said above, WRC is for cylinder-cylinder intersections.

Richard,
I am just asking about anchor and cnode nozzle neck (can we put anchor and cnode on nozzle neck equipment for nozzle loading )

If you model the nozzle as a rigid anchor with no flexibility, then you should get conservative results for piping stress and nozzle loads. Note that the nozzle may still have displacements due to thermal growth of vessel. You then would still have to evaluate the nozzle loads for acceptability, by either comparisons to allowable nozzle loads tables, review by vessel vendor, or FEA methods perhaps.

Dear Dave Clark & Richard,

I think what i am saying you not understand.
I modelled equipment with nozzle.
means i moddeled equipment one side anchor and other side holddown+guid (for sliding support )
My question is when i moddle the nozzle and I creat anchor and CNODE on nozzle neck forcheking the nozzle loads.
this ok or not.when i am not using the wrc.
i hope you can relpy what i am saying.

rgards,
smapiping.

Yes, it is correct. Place an anchor on the nozzle with a cnode on the vessel shell. It is the nozzle to shell junction you have to check.
Alternatively if you use nozzle flexibilities you have to define the nozzle node and the vessel node which is the nozzle to shell junction.
If you give the loads at flange face, note that forces will create additional moments at the nozzle to shell junction.