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STEAM NOZZLE LOAD CALCULATION
- Thread starter mihir5577
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There are two main references: WRC-107 and WRC-297. The procedures can get tedious when done by hand, and involve reading factors off a number of various charts. I think some of the pressure vessel design handbooks may also cover nozzle design in less detail.
This type of design is included in various pressure vessel design programs, as well as finite element software that can accomplish the same thing. I'm not aware of any online resource for actually doing the analysis, and would be wary about using a method I didn't understand.
The analysis in those references is to evaluate local bending and membrane stresses due to external loads on a nozzle. That should not be confused with the design of nozzle reinforcement, which is considerably simpler.
This type of design is included in various pressure vessel design programs, as well as finite element software that can accomplish the same thing. I'm not aware of any online resource for actually doing the analysis, and would be wary about using a method I didn't understand.
The analysis in those references is to evaluate local bending and membrane stresses due to external loads on a nozzle. That should not be confused with the design of nozzle reinforcement, which is considerably simpler.
One note: the WRC methods calclate STRESSES due to external LOADS. Calculating the loads is another matter, and (I assume) is done from analysis of piping or by evaluating other sources of loads. Given the applied loads, stresses in cylinders can be calculated per WRC methods.
Regards,
Mike
Regards,
Mike
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- #7
For information on Welding Research Council (WRC) Bulletins, go to
You still have not answered the question of whether you are trying to determine the LOADS on the nozzles, or the STRESSES in the nozzles due to applied loads. Which of these two are you trying to determine/calculate.
You still have not answered the question of whether you are trying to determine the LOADS on the nozzles, or the STRESSES in the nozzles due to applied loads. Which of these two are you trying to determine/calculate.
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- #9
One of the WRC bulletins will do the job, better if you can find some software.
As I recall, WRC-107 will calculate stresses in the main cylinder only, while WRC-297 does the nozzle as well. Can anybody confirm or deny?
WRC-107 does not use X,Y,Z coordinates, but uses vessel circumferential and longitudinal and nozzle torsional coordinates, but the X,Y,Z loads can be placed in the vessel coordinate system fairly easily. Not sure about 297.
Good luck,
Mike
As I recall, WRC-107 will calculate stresses in the main cylinder only, while WRC-297 does the nozzle as well. Can anybody confirm or deny?
WRC-107 does not use X,Y,Z coordinates, but uses vessel circumferential and longitudinal and nozzle torsional coordinates, but the X,Y,Z loads can be placed in the vessel coordinate system fairly easily. Not sure about 297.
Good luck,
Mike
DavidRibeiro79
Mechanical
Any good pressure vessel software, eg Codecalc, will make this calculation easy for you. Once your pipe stress engineer can confirm the nozzle loads, it becomes really simple with this tool.
An discretionary note, some programs extrapolate the curves in WRC 107 / 297 bulletins, which is often considered unacceptable by industry. In cases like that one often relies on FEA to determine the stress levels. See programs like NozzlePro, very nice!
May I recommend that you consult with an expert to determine these stresses, as I assume this will be a first time excersise for you?
An discretionary note, some programs extrapolate the curves in WRC 107 / 297 bulletins, which is often considered unacceptable by industry. In cases like that one often relies on FEA to determine the stress levels. See programs like NozzlePro, very nice!
May I recommend that you consult with an expert to determine these stresses, as I assume this will be a first time excersise for you?
Bednar's "Pressure Vessel Design Handbook" has a much simplified method of analysis for nozzle load streses, useful for rough sizing calc's. Also, don't forget that if it's a flanged nozzle, oftentimes the flange "equivalent pressure" is what's limiting {Kellogg & Stikvoort analyses}
mihir5577
are talking about Sec I of the B&PV Code? or is it SEc VIII-1? it look to me as a SEc I question, being confused no one can assume
For SEc VII-1 you can find software, for Sec I you may have to do it by hand calc.
can you specify what type of load you are calc, is it weld pass or outside loads on the nozzle?
genb
are talking about Sec I of the B&PV Code? or is it SEc VIII-1? it look to me as a SEc I question, being confused no one can assume
For SEc VII-1 you can find software, for Sec I you may have to do it by hand calc.
can you specify what type of load you are calc, is it weld pass or outside loads on the nozzle?
genb
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