Nozzle - Design Information
Last Updated: 2021.6
Pressures
Override: When this box is checked, the Pressure field can be changed to a pressure other than that of the host. If the box is cleared, the Pressure field is locked to the host pressure.
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.
Opening Information
Nozzle Path: If the opening is in a Category A joint, select Cat. A. If the nozzle is in ERW or autogenously welded pipe and it is not clear where the welds are or it is clear that the opening is in one of the joints, select ERW/Auto. For all other cases, select None. This setting affects the value of E1 used to determine the value of A1 in the reinforcement calculations; see the definition of E1 in UG-37 for more information.
Access Opening: If the nozzle is to be used only for access or inspection purposes, select an option (other than "None") from the drop-down menu. This will give relief from the UG-45(b) nozzle neck thickness calculations. Selecting "Elliptical Manway" will not change the calculations to reflect an elliptical neck.
Nozzle or reinf. Outside spherical portion: For nozzles in torispherical or ASME F & D heads, select the box when any of the reinforcement of the nozzle neck crosses into the knuckle region. If the nozzle and its reinforcement (including any reinforcement from the head) are completely within the dish of the head, the box may be left clear. This will affect the value of tr used to determine the values of A and A1 in the reinforcement calculations. See the definition of tr in UG-37 for more information.
Nozzle or reinf. Outside 80% of Center: For nozzles in elliptical heads, select the box when any of the reinforcement of the nozzle neck crosses outside the 80% region, which is defined as a circle centered on the head axis that includes 80% of the head skirt inside diameter. If the nozzle and its reinforcement (including any reinforcement from the head) are completely within the 80% region, the box may be left clear. This will affect the value of tr used to determine the values of A and A1 in the reinforcement calculations. See the definition of tr in UG-37 for more information.
Nozzle 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.
Nozzle Dimensions
Inside Diameter: The component inside diameter in the new condition.
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. This efficiency is for the long seam in the nozzle neck and does not represent the joint efficiency for the joint attaching the nozzle to its host or for any joints in the host that the nozzle penetrates.
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.
Groove Depth: This field represents the depth of the groove weld in the nozzle neck for abutting nozzle details and for details inserting the nozzle neck. The default is full penetration value. This field will only be available for details that include groove welds.
Penetration: Only available for the UW-16(k) or Partial Penetration nozzle configurations, this field represents the partial depth that the nozzle neck is inserted into the host wall.
Inside CA: Corrosion allowance on the inside of the component (concave side).
Dimension L: The radial offset of the nozzle, defined as the axis to axis distance between the nozzle and a hypothetical nozzle that is radial. This field is only available for tangential nozzles and is used in the calculation of the developed opening for nozzles in cylindrical shells, hemispherical heads, and elliptical heads. In dished heads, this is the same as the distance from the center of the head when the nozzle axis is parallel to the head axis.
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.
Developed Opening: The chord length (in the new condition) of the opening as defined in Figure UG-40 for the nozzle type being used. Chord length is most commonly determined from the ID of the nozzle neck, however certain details, such as UW-16(k), are based on the hole made in the host to accommodate the nozzle. The corroded version of this value is used as d in the various nozzle calculations, including the reinforcement exemption criteria in UG-36(c)(3)(a).
Custom Developed Opening: Select this box to manually enter values for all nozzle angles. Doing so will also require manual completion of the "Developed Opening" and "Corroded Developed Opening" fields.
Minimum Thickness Per Service Type: This dropdown allows the user to select the UG-16(b) service thickness they would like for the nozzle design. This is set per each nozzle component. This thickness must be met after undertolerances, forming allowances, and corrosion allowances are removed. For low pressure, low loading designs, this may govern the thickness of the design. This defaults to the vessel setting; but may be changed.
Custom: This value will set a custom minimum thickness per service type. This value is only used if "Custom" is selected for Minimum Thickness Per Service Type.
tb1 and tb2 CA: Determines the corrosion allowance used in the UG-45 calculations to determine tb1 and tb2; this field defaults to Nozzle CA for new vessels and patched vessels.If Nozzle CA is selected, the nozzle corrosion allowance will be used. If Host CA is selected, the calculations will use the corrosion allowance of the host.
UG-45 Comparison: Select the number of digits from the nozzle thickness to compare to the UG-45 thickness requirement. The default value is four decimal places for customary units and two decimal places for metric units. The number of decimal places used is examined after any pipe tolerances have been considered.
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