Inner Vessel

This section displays summary information on the inner vessel component that is connected to the jacket closure.

Jacket

This section displays summary information on the jacket component that is connected to the jacket closure.

Closure

Pressure: The internal design pressure (pressure on the concave side). This value is gauge pressure. When “Solve for Thickness” is selected, this value is an input and should not include static head. When “Solve for Pressure” is selected, this value is a result. In the latter case, it represents the total internal pressure (design pressure plus head) that the component can handle and meet code in the absence of any other loadings.

Static Head: The internal pressure (pressure on the concave side) resulting from the static head of the fluid. The user must determine this value and input it accordingly. It will be added to the Pressure input and the sum will be used in the internal pressure calculations for the component. This field will not be present when “Solve for Pressure” is selected.

Temperature: The maximum mean metal design temperature for the internal pressure case as defined in UG-20(a).

CA: Corrosion allowance on the inside of the component (concave side).

Efficiency: The joint efficiency of the component, which is determined from Table UW-12 for welded joints and may also represent ligament efficiency per UG-53. When both ligaments and welded joints exist, the lowest efficiency is used. See Appendix L for further help in determining the efficiency.

Nominal (tc): This value is in the new condition. For the component to pass, this value must be at least the sum of the thickness necessary for pressure and temperature, corrosion allowances, and forming allowances or under-tolerances. If the thickness necessary for pressure and temperature is less than the thickness required by UG-16, the nominal thickness must be at least the sum of the UG-16 thickness and the tolerances, etc. In some cases, under-tolerance is not considered (e.g., for nozzle reinforcement, the under-tolerance of the nozzle neck is ignored). When “Solve for Thickness” is selected, the software will determine the smallest standard size that passes. For Jacket closures, this value must also meet certain detail requirements.

Material

Material: A brief description of the component material. When the material selection dialog is used, the default description is based on settings on the Materials-Misc. tab under Tools > Defaults. For example, if the settings are for Spec and Type/Grade and the material is SA-516 Grade 70, this field will show SA-516 Gr. 70. If the settings are instead just for Spec, the field will show SA-516. The field may be edited by the user to say anything without breaking the relationship to the material database; while this flexibility can be very helpful, the user must take care to enter correct information.

Condition: A brief description of the component material. Similar to the "Material" field, the description will default a certain way based on settings on the Materials-Misc. tab under Tools > Defaults when the material selection is used. This field may be edited by the user without breaking the relationship to the material database. As with the “Material” field, the user must take care to enter correct information.

Density: The material density based on table PRD from Section II, Part D. For those materials that did not have a clear match in this table, every effort was made to assign conservative values. Manually editing this field will sever the connection to the material in the database as indicated by the "Unlisted Material" caption.

Stress (Hot): The material allowable stress at the temperature listed for the internal pressure condition. When a 3.5:1 safety factor is specified in the vessel screen, this value comes from Section II, Part D (Table 1A for Ferrous Materials, Table 1B for Non-Ferrous Materials, and Table 3 for Bolting). If a 4:1 safety factor is specified, this value is calculated based on the ultimate strength from Table U in Section II, Part D; furthermore, the value is limited to the values listed in the allowable stress tables for yield and creep governed cases. In cases where the temperature listed for the internal pressure condition exceeds the highest temperature entry for this material’s stress line, the value will be zero. Manually editing this field will inform the software that the user is defining the material differently than what is stored in the database and the connection to the material in the database will be severed. This is indicated by the “Unlisted Material” caption.

Stress (Cold): The material allowable stress at 70 °F (20 °C). When a 3.5:1 safety factor is specified in the vessel screen, this value comes from Section II, Part D (Table 1A for Ferrous Materials, Table 1B for Non-Ferrous Materials, and Table 3 for Bolting). If a 4:1 safety factor is specified, this value is calculated based on the ultimate strength from Table U in Section II, Part D; furthermore, the value is limited to the values listed in the allowable stress tables for yield and creep governed cases. Manually editing this field will sever the connection to the material in the database as indicated by the “Unlisted Material” caption.

Factor B table: The external pressure table assigned to the material in the allowable stress tables in Section II, Part D. The table is used to determine the external pressure strength of the component and also the longitudinal compressive strength. Selecting a Factor B table other than the one assigned to the material will sever the connection to the material in the database as indicated by the “Unlisted Material” caption.

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