Vessel Nozzle loads (Silencer) Vs Vendor data

Posted by: runner

Vessel Nozzle loads (Silencer) Vs Vendor data - 12/26/10 12:46 AM

Hi to all,
vendor has provided in silencer data sheet Max allowable nozzle loads. pipe stress analysis showing Max loads with respective design conditions. Question is should I follow WRC 297/107 or Should I follow vendor information.

If we apply common sense we need to follow vendor information with respective CAESAR II loads, but I am getting 5 time more then vendor design, I am trying to change my routing to minimum the moments and loads. Is there any other way to do?

Thanks
Posted by: corne

Re: Vessel Nozzle loads (Silencer) Vs Vendor data - 12/26/10 02:27 AM

You should follow vendor data. If you use WRC and the allowables according to WRC are higher than vendor data, it's your reponsibility, and I don't think that is what you want.

Have you entered nozzle flexibility in your pipe stress analysis? That will reduce the nozzle forces.
Posted by: runner

Re: Vessel Nozzle loads (Silencer) Vs Vendor data - 12/26/10 06:37 AM

your right...but vendor data I have only below information

Head crown radius = 68 in
Head wall thickness = .1968 in
Head Material allowable stress = 12000 psi
Inlet Design Pressure = 228 psi
Inlet Design Temp = 770 deg F
Nozzle outside Diameter = 18 in
Flange allowable pressure at 770 Deg F 1045 psi
Flange Raised face OD 21 in
Max allowable axial load (+=up) Fz 4116 Ib
Max allowable overturning moment X-plan (Mx) 3430 ft.lb
Max allowable overturning moment X-plan (My) 3430 ft.lb

Now tell how to proceed with this information for better results in my moments.

Posted by: Rajinder Singh

Re: Vessel Nozzle loads (Silencer) Vs Vendor data - 12/27/10 12:37 AM

runner,
Change pipe routing and supports to qualify nozzle loads. If this doesn't work than try hard to minimize nozzle loads as much as you can and submit loads to vendor for approval. Doing so you will get some additional time to look at and study the system in more depth.
WRC 107/ 297 should be kept secondary. Always keep in mind that we can't use WRC107/ 297 to solve all problems. They have certain limitations. If you use WRC then it should be highlighted and discussed with seniors and also document properly.
I am afraid that I can't tell you how to proceed with the given information for better results in moments on this forum.