Tubesheet - Floating

Owned by Former user (Deleted)
Dec 11, 2015
3 min read

(Fixed, Floating, and U-Tube)

Floating Side Information

Outside Diameter: The component diameter in the new condition.

Inside Diameter: The component diameter in the new condition.

Channel Type: Select Channel Shell or Channel Head. At this time, only Hemispherical Channel Heads are available for use in tubesheets per ASME Section 8, Div 1, Part UHX.

Operating Bolt Load: The internal pressure operating bolt load. This applies to configurations b, c, d, e, f, B, C, and D. Wm1s represents the shell side operating bolt load and Wm1c represents the tube side operating bolt load.

Radial Distance: The moment arm from the bolt circle to the diameter on which the gasket reaction acts.

Bolt Circle: The diameter of the circle that passes through the center of each bolt.

Channel Thin Out: The material thickness lost to the forming process. To determine the minimum thickness after forming, the un-corroded nominal thickness is reduced by this amount.

(Defl): The floating channel gasket inside diameter, but not less than the floating channel flange inside diameter. If tubesheet acts as LAP, this is the diameter where the shear stress is acting. This applies to configuration C only.

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

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.

Gasket Load Diameter: Diameter of the gasket load reaction.

Bolt Load: The flange design bolt load. This applies to configurations b, c, d, e, f, B, C, and D. Ws represents the shell side design bolt load and Wc represents the tube side design bolt load.

Midpoint of contact between flange and tubesheet: The diameter to the midpoint of contact between the lap flange and the tubesheet. This field is only available for configurations c, f, and C.

Per UG-23(e), calculate using: Select whether to calculate the allowable primary plus secondary stress using 3xS or 2xSy. Caution: If 3xS is selected and the value of S is determined at 90% of Sy, the allowable primary plus secondary stress will be 2.7xSy.

Floating Channel 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.

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.

Poisson: Poisson's ratio for the selected material.