What is used to strengthen the shell of a vessel where a hole was cut for a nozzle?

What is used to strengthen the shell of a vessel where a hole was cut for a nozzle?

• A. Reinforcing pad
• B. Gusset plate
• C. Flange extender
• D. Spacer ring

Answer: (A)

The key idea is strengthening the shell around the hole to carry the nozzle load. When a hole is cut in a vessel shell, the local thickness is reduced and the remaining metal around the opening experiences high stress from internal pressure and the nozzle connection. A reinforcing pad is welded around that opening, increasing the local thickness and creating a smooth, gradual transition for stresses from the nozzle into the shell. This distributes the load over a larger area and to the shell, which helps prevent cracks and leaks at the cut. Gusset plates are generally used to brace structural joints at angles, not to reinforce a circular shell around a nozzle. A flange extender changes the flange size or alignment rather than strengthening the shell itself. A spacer ring is used to maintain spacing or alignment, not to reinforce the shell around an opening.

The key idea is strengthening the shell around the hole to carry the nozzle load. When a hole is cut in a vessel shell, the local thickness is reduced and the remaining metal around the opening experiences high stress from internal pressure and the nozzle connection. A reinforcing pad is welded around that opening, increasing the local thickness and creating a smooth, gradual transition for stresses from the nozzle into the shell. This distributes the load over a larger area and to the shell, which helps prevent cracks and leaks at the cut.

Gusset plates are generally used to brace structural joints at angles, not to reinforce a circular shell around a nozzle. A flange extender changes the flange size or alignment rather than strengthening the shell itself. A spacer ring is used to maintain spacing or alignment, not to reinforce the shell around an opening.