PVElite heat exchanger tubsheet

Tubesheet Properties

Description

Enter the description for the tubesheet. The description will appear on your final report.

Distance From Node

Enter the distance from the shell to the outer face of the nearer tubesheet. As there are a number of configurations, this sketch gives an example where 'L' is the distance from node:

Tubesheet Type

Choose the type of tubesheet that you will analyze. ASME has classified tubesheets in to four distinct types.

Fixed Tubesheet Exchangers are subject to loads arising from differential thermal expansion between the tubes and the shell. They have stationary tubesheets on both sides. Fixed tubesheet exchangers can be further classified into Configurations A, B, C or D. U-tube Exchangers are categorized either as integral with the shell, channel, both or gasketed on both sides. Floating Tubesheet Heat Exchangers have a stationary tubesheet and a floating tubesheet. Click this link for permitted configurations.

The program automatically resets other inputs on this dialog, based on the selected tubesheet type.

Some ASME UHX Tubesheet configurations are illustrated below (for TEMA Tubesheets configurations click here):

Tubesheet configurations for EN-13445 Exchangers are very similar to ASME Part UHX configurations. One main difference is that the EN Code specifically deals with flanged extensions that have a full-faced gasket. These geometries in the EN Code are typically specified with prime symbol following the connection type (like b'). Note that these are not selections on the pull downs for the various types. When flanged extensions have gaskets that extend past the bolt circle, PV Elite will automatically apply the EN Code rules that apply to these types of extensions.

Heat Exchanger Help - Tub... Page 1

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Tubesheet is integral with the Shell and is gasketed on the Channel side and is not extending as a flange.

Tubesheet is integral with the Shell and is gasketed on the Channel side and is extending as a flange.

Tubesheet is gasketed on both the Shell and the Channel sides and is not extended as a flange. In an alternative arrangement the tubesheet is extending as a flange.



Stationary and U-tube Tubesheet configurations allowed per ASME Part UHX:

Tubesheet is integral with both the Shell and the Channel. This is a fixed tubesheet exchanger, as a flanged and flued expansion joint is used to reduced the differential thermal expansion, between the tubes and the shell.

Configurations Description

a Tubesheet integral with both Shell and Channel

b Tubesheet integral with Shell, gasketed with Channel, with Tubesheet extended as a Flange

c Tubesheet integral with Shell, gasketed with Channel, with Tubesheet not extended as a Flange

d Tubesheet gasketed with both Shell and Channel

e Tubesheet integral with Channel, gasketed with Shell, with Tubesheet extended as a Flange

f Tubesheet integral with Channel, gasketed with Shell, with Tubesheet not extended as a Flange



Floating Tubesheet configurations allowed Per ASME Part UHX:

Fixed Tubesheet configurations allowed Per ASME Part UHX:

The following image shows various tubesheet attachment types.

Outside Diameter

Enter the outside diameter of the tubesheet.

Tubesheet Thickness

Enter the Tubesheet Thickness in uncorroded condition. If it is a re-rate, then the actual measured thickness is typically used.


A Tubesheet integral

B Tubesheet gasketed and extended as a Flange

C Tubesheet gasketed and not extended as a Flange

D Tubesheet Internally Sealed


a Tubesheet integral with both Shell and Channel

b Tubesheet integral with Shell, gasketed with Channel, with Tubesheet extended as a Flange

c Tubesheet integral with Shell, gasketed with Channel, with Tubesheet not extended as a Flange

d Tubesheet gasketed with both Shell and Channel



Corrosion Allowance Shell Side / Channel Side

Specify the corrosion allowance on the shell side (the inner face of the tubesheet), and the corrosion allowance on the channel side (the outer face of the tubesheet facing the channel side).

Depth of Groove in Tubesheet (If Any)

Enter the depth of a groove in the tubesheet, used to locate the channel partition plate and its gasket. If there is no groove for example in a single pass exchanger, this value is zero.

Weld at Back of Tubesheet (if any)

If the tubesheet is welded to shell and/or channel then specify the fillet weld length at the back of the tubesheet.

Tubesheet Assembly is down/left

Check this box if you have one of the following cases,

A horizontal U-tube exchanger modeled with tube bundle facing left and the tubesheet on the right. A vertical U-tube exchanger.

Tubesheet Extended as a Flange

If the tubesheet is extended as a flange, it is subject to the bolt load from the mating flange.

Thickness of Extended Portion of Tubesheet

If the tubesheet is extended as a flange, specify the thickness of the portion of the tubesheet that is extended for bolting. Refer to the following illustration,



Tfr/T Ratio of Required thickness of Tubesheet Flanged Ext. / Tubesheet (Optional)

If it is desired to reduce the required thickness of the tubesheet flanged Extension, then specify the ratio of the Required thicknesses of Tubesheet Flanged Ext. and the Tubesheet. This is used in TEMA RCB 7.1342 for U-tube tubesheet exchangers

This is an optional input and this ratio should be less than 1.0 and more than 0.2. The default value is 1.0.

Bolt load transferred to Tubesheet?

Check this box if the bolt load is transferred to the tubesheet, which is extended as the flange.

If the tubesheet is gasketed with both the shell and channel flanges, then tubesheet can still be extended but the bolt load is not transferred to the tubesheet extension. In that case you can uncheck this box. But, carefully consider all the possible cases such the hydrotest.

If this box is unchecked then the required thickness of tubesheet extension is not computed.

Un-tubed Lane area

This is the total area of all the untubed lanes on the tubesheet. If there is no pass partition lane then this area is 0. This input is only needed for ASME code analysis.

See the figure below for a single pass exchanger, this area is UL1 * Do.



The maximum limiting value of AL is 4*Do*p. Where, Do = Equivalent diameter of outer limit circle. p = tube pitch UL1 = Distance between innermost tube hole centers (width of pass partition lane)

PD 5500 - How are the Tubesheets Clamped

If there is a fixed tubesheet or a floating tubesheet, the method of clamping is important. Using the table below determine the most appropriate method of clamping for each tubesheet,

Tubesheet types discussed in PD 5500 code:

Stationary Tubesheet Floating Tubesheet

Simply Supported Simply Supported

Simply Supported Clamped

Clamped Simply Supported

Clamped Clamped





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PVElite heat exchanger tubsheet