Expansion of Tube to tubesheet joint

[krishna mudhale]

Dear Experts,
Please clarify the below queries about Tube to tubesheet joint
expansion-
1)when & why expansion is necessary .
2)Difference between contact(light) & heavy expansion and what its
range.
3)For strength weld is expansion necessary.
4)By expanding the tube what are the applications.


With warm regards
Krishna M. Mudhale.

[Purav Desai]

Dear,

 

Please see reply as below;

 

1)when & why expansion is necessary .

Expansion is necessary in all cases because tube hole in ubesheet is slightly higher than tube OD. So if we do not expand it will cause crevice and ultimately tends to leakage.

 

 2)Difference between contact(light) & heavy expansion and what its range.

For Heavy expansion, normally grooves shall be provided in tubesheet as per TEMA RB-7.24. Tubes will be expanded in such a way that it will flow in these grooves. In Heavy expansion normally 5% thinning of tube thickness occurs.

 3)For strength weld is expansion necessary.

For strength welded tube to tubesheet joints, contact expansion is necessary as explained in (1) above.

 4)By expanding the tube what are the applications.

Tubes are expanded using standard roller expander or sometimes using hydraulic expander.

Hope this will help.

 

 

Regards;

 

Purav Desai.

 

 

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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

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Regards;

Purav DESAI

purav...@gmail.com

[GOPU NAIR]

Dear Krishna 1. Expansion of tubes into the tubesheet is necessary when the clearance between the tune OD and tubesheet ID can not be left as is to allow the gas or liquid to get trapped into. 2. Light expansion is just closing the clearance but strength expansion is to have the tubes forced and embedded into the tubesheet. Light expansion is normally 0 to 3% whereas the strength expansion is between 6 to 8%. 3. For strength welded joints expansion is needed when the entrapment of process fluid between tube and tubesheet can not be tolerated. 4.  Question is not clear God bless you gopu --- On Mon, 10/12/12, krishna mudhale <kmud...@gmail.com> wrote: From: krishna mudhale <kmud...@gmail.com> Subject: [MW:16186] Expansion of Tube to tubesheet joint To: "Materials & Welding" <material...@googlegroups.com> Date: Monday, 10 December, 2012, 9:31 PM Dear Experts,Please clarify the below queries about Tube to tubesheet joint

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