SHELL AND TUBE HEAT EXCHANGER (Tube Sagging Problem)

[hammad_nrl]

Guys we have a shell and tube heat exchanger whose data is as follows:

Type: AES
No of tubes: 402
Material: A-213 T5

Operating Pressure:
Shell: 149.3Psig Tube:127Psig

Operating temperature:
Shell: 352-361 deg.C Tube: 514-626 deg.C

Service:
Shell: Naptha + H2S Tube: Fuel oil + S

We have countering problem of tubes sagging. Kindly tell me why the exchanger tubes sagging
Is any one knows the possible reasons of tube sagging?
I will be waiting fir your response

Regards;
Hammad

[mikeyles]

Can you give further information on the HEX config, eg fixed tube tubesheet with or without shell bellows, , floating head etc.....TEMA has diagramatical info on types.

If you have access to the excahnger design calculations, check if they have considered the worst case differential metal temperature between shellside and tubeside as you have upto a 274deg C difference that the heat exchanger has to cope with in terms of thermal expansion.

[hammad_nrl]

The heat exchanger is of AES type.
i.e.straight and Floating tube sheet and no bellow in shell design

[willianstz]

Hello friend,
Besides the already mentioned by thermal expansion mikeyles, which can contribute to sagging of the tubes is excessive deformation in tubesheets, and incorrect specification of the tube material or thickness. The ASME section VIII div. 1 part UHX provides seven conditions of loading for tubesheets, including thermal expansion.
If you can, please send a drawing and project data over the heater for a more thorough examination.
willianstz@gmail.com

[irma reyes martinez]

2you must have careful, the fluids is haigh pressure, you must select the adecuate tubbing, besides you must select the baffles Ds/5, the minoer distance of separation, because es when the tubbingn pluggs

[rioca57]

The A-213 T5, it supports the 2010 Section II, Part D (METRIC) (see page 39, line 22) to 649 ° F (342.7 ° C) and tube-side heat exchanger works between 514 ° C to 626 ° F. In 2010 SECTION II, PART D (METRIC), indicated that the ASME-1 (Applicability and Max. Temperature Limits) supports this material (A-213 T5) to 342.7 ° C.

I think you should review the design and your process variables. There excessive heat input, whose temperature is above the allowable bearing material.

I hope this helps

greetings brother

[rioca57]

The A-213 T5, it supports the 2010 Section II, Part D (METRIC) (see page 39, line 22) to 649 ° F (342.7 ° C) and tube-side heat exchanger works between 514 ° C to 626 ° C[/U]. In 2010 SECTION II, PART D (METRIC), indicated that the ASME-1 (Applicability and Max. Temperature Limits) supports this material (A-213 T5) to 342.7 ° C.

I think you should review the design and your process variables. There excessive heat input, whose temperature is above the allowable bearing material.

I hope this helps

greetings brother