Engineering calculator reviewed for preliminary design use · Last updated: March 2026
Perform nozzle reinforcement calculation per ASME Section VIII UG-37. Calculate required area A_required and available reinforcement area from shell excess thickness, nozzle wall, and reinforcing pad. Verify adequacy of reinforcement for pressure vessel code compliance.
Nozzle Reinforcement Calculator (ASME UG-37)
When an opening (nozzle) is cut into a pressure vessel shell, the removed metal must be replaced by reinforcement. ASME Section VIII Div.1 UG-37 specifies reinforcement requirements using the area replacement method.
An opening in a pressure vessel shell removes material that was carrying pressure loads. The remaining material around the opening, plus any added reinforcement, must carry the redistributed stress. ASME UG-37 ensures adequate area is available.
When is a reinforcing pad required?
A reinforcing pad is needed when the available reinforcement area (from excess shell and nozzle wall thickness) is less than the required area. Small nozzles in thick shells often self-reinforce; large nozzles usually need pads.
These results are preliminary estimates for screening-level design use. They do not replace detailed engineering, code compliance verification, or vendor-certified calculations.