Stiffening Ring 1

[lcmechengr]

I have an exisitng vessel that will require me to place a nozzle in the same location as an external stiffening ring. My thoughts were to replace the stiffening ring with the same or greater moment of inertia that would have to be removed by "boxing" in the nozzle. Does anyone see a problem with this?

 

[doct9960]

lcmechengr,

It needs to be accepted by the AI. See Interpretation: VIII-1-89-275

"Question: When a stiffener ring extends completely around the outside circumference of a cylinder and intersects a nozzle, may a connection between nozzle and stiffener be made if the required moment of inertia of the ring shell section is maintained through the nozzle per UG-29(b) and design and construction details are submitted and accepted by the Authorized Inspector per U-2(g)?
Reply: Yes."

 

[innovation2]

The code does allow breaks in vacuum rings, I can't quite remember the section, but I believe that you are allowed up to a 90 degree break. Please someone correct me if I am wrong.