API-650 Nozzle Reinforcement 1

[Schuppert]

When checking shell openings for the nozzle reinforcement required is it acceptable to use the "One Foot Method" for the required nozzle neck thickness. I believe any shell or nozzle thickness in excess of that required by this method is available for reducung the size of the repad but want to be sure. Does anyone know of any sample calculations available for Openings in API-650 Tanks.

Thank you.

 

[JStephen]

With ASME vessel nozzles, the neck material that may be used in reinforcing calcs is that in excess of the design neck thickness.

With typical atmospheric tanks, the required neck thickness based on hoop stress is usually very small, and the standards just specify that a certain length of neck may be used as reinforcing, without a requirement of deducting the "required" neck thickness.

The atmospheric tank standards allow a longer length of neck to be included as well, but do not include weld metal in the calculations, unlike ASME.

 

[IFRs]

Yes, but please check API 653 for the exact equations and assumptions.

 

[jte]

Schuppert-

Looks like you got your answer. The forum809 will probably get you more coverage next time.

jt

 

[JoeTank]

It would not be appropriate to use the one-foot method to calculate the nozzle neck thickness. Drop the "-1". In order to modify the requirements of the standard nozzle reinforcements, you must obtain approval of the purchaser.

Joe Tank