Lifting Lug - General Information

Owned by Former user (Deleted)
Last updated: Oct 04, 2024 by Tiradej Bunyarattaphantu
6 min read

Last Updated: 2022.11


Description: The label given for the component. It will appear in the component pane, the report dialog, the summary pane, and at the top of the component report. This will default to the component type and component number. For example, the third nozzle for the vessel will start with a description of Nozzle 3.

Mark: A shorthand reference for the component. It will also appear in the component report. The default entry will be an abbreviation of the component type and the component number. For example, the second jacket shell for the vessel will start with a mark SJ2.

Vessel Weight: When the lifting lug is created, this value will be automatically completed with the calculated weight of the shells, cones, and heads at the time the lug was created. If components are added to the vessel after the creation of the lifting lug, this field will not update. The weight that is calculated here for the initial creation of the lifting lug does not include any weights or content listed in Vessel > Attachments/Loadings, no skirt weight, and no nozzle or flange weights.

Vertical Lift Angle (α): The angle formed between the vertical and the direction the lift force is pulling (see the figure on the General Information tab in the software for more information).

Impact Factor: A multiplier on the vessel weight to account for dynamics on the vessel during the lift. For example, if 5000 lb. is entered as the vessel weight and 1.5 is entered for the Impact Factor, the weight will be increased to 7500 lb. for the calculations.

Calculate Localized Stresses: Select this box to also check local stresses in the host shell.

Support Types: Select a lifting lug type from the available options (see the figure for more information). Types 1 and 2 are for horizontal vessels or for heads; types 3 and 4 are for vertical vessels.

Lug Location

Distance from Reference Line: The distance from the top of the host shell measured along the axis of the vessel to the bottom of the lug for vertical vessels, type 3 and 4 lifting lugs. On horizontal vessels, type 1 and 2 lifting lugs, this is the distance from the reference line datum measured along the axis of the vessel to the middle of the lug.

Calculate as a Pair: Enables entry of the "Distance from Reference Line" for both a right and a left lug. This option is only available on horizontally oriented vessels.

Lug Orientation: Determines the position of the lug around the shell and is only an available option on vertically oriented vessels. 

Host Information

Description: Displays the description of the host as entered in the component's General Information tab.

User Defined: Select this box to manually adjust the host values. By default, these values are imported from the host component.

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

Thickness: 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. The user is able to manually edit this value.

Radius: The component radius in the new condition.

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.

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 and the design temperature listed for the internal pressure condition. In cases where the temperature listed for the internal pressure condition 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.

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.

Yield Strength: The material yield strength at the temperature listed for the internal pressure condition. This value comes from Section II, Part D, Table Y-1. In cases where the temperature listed for the internal pressure condition exceeds the highest temperature entry for this material’s yield line, 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 calculate the yield strength using the external pressure chart and the method described in UG-28(c)(2) Step 3. This is more common with non-ferrous materials. If no match is found and the software cannot perform the described calculation, this 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.