Select the jacket type that you are analyzing from the list. If you cannot decide the type that best suits your model, then select Type 2. If this is not appropriate, then the software gives you a warning message.
The software calculates the required thickness of the jacket, closure bar, and the internal chamber (cylindrical / conical shell, or head covered by the jacket). The code gives weld sizes, which must be adhered to because they ensure full integrity of the jacket attachment to the vessel. ASME VIII Div 1 Appendix 9 sets out 5 basic jacket configurations. For more information, see Figure 9-2 in the Code.
In a type 3 jacket arrangement, there is no closure bar, however the welding is critical, and the notes set out in the Code must be adhered to.
Typically, the jacket is attached by means of a closure bar as shown here:
The closure bar can be a simple rectangular section ring as displayed above, or it can be more elaborate as displayed in Appendix 9 of the Code.
Verify the inner shell/head for external pressure using (any) vacuum plus the Jacket Pressure and consider the Design Length of the Jacket section L.