Ring Information

Stiffener Location: Select whether a stiffening ring is present and, if so, whether the stiffener is in the shell or the cone.

External CA: Corrosion allowance on the outside of the component (convex side). This field is available for internal heads and for the inner components of a jacketed vessel.

Stiffener Dimensions: Enter the dimensions for the stiffener in the appropriate fields. See the diagram for more information.

Description: The label given for the component.

Ring Type: Select the type of stiffener from the available options.

Stiffener 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-Mic. 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.

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.

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 this temperature 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.

Modulus of Elasticity: The material modulus of elasticity based on the TM tables from Section II, Part D. The value shown here is based on the applicable TM table at the temperature listed for the internal pressure condition. In cases where this temperature exceeds the highest temperature entry for this material’s TM table, the value will be zero. There are several materials that do not have clear matches in these tables. When a clear match cannot be found by the software’s assignment criteria, the software will instead retrieve the modulus of elasticity from the external pressure chart assigned to the material. If this attempt also fails, then the value will be zero. This is more common with non-ferrous materials. Manually editing this field will sever the connection to the material in the database as indicated by the “Unlisted Material” caption.

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