HEX end cap divider plate vibration

[KevinNZ]

Can anyone please suggest a detail to reduce the vibration of the divider plate in the end cap of a two pass HEX? See attached.

This plate in vibrating and cracking the welds where it is attached to the head, Also moves across the contact point at the tube sheet and stuffs the gasket.

We are thinking of installing support stay rods between the plate and the head.

There is around a 50C temperature difference between the flows.

Thanks

 

[SnTMan]

KevinNZ, staybars are often used, especially in larger diameters. Normally placed on the inlet side.

Worth a try, I'd say.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Tothesky]

Is there NO Groove for Passpartition Plate(Divider Plate) on Tubesheet?
Passpartition nornally to be inserted to groove on tubesheet. The deep of groove is 5mm from surface of tubesheet.

Moon.

 

[r6155]

you comply with API 660 or TEMA?

Regards
r6155

 

[KevinNZ]

Tothesky, yes there is a groove but this is not holding the plate. The groove is worn from vibration.

R615. Do API660 and TENA have different requirements for supporting the plate?

 

[btrueblood]

Any chance of re-orienting the inlet nozzle to reduce direct impingement of the flow on the divider?

 

[KevinNZ]

Moving the nozzle would not be an option but internal flow vanes could be.

 

[r6155]

KevinNZ
You need to read and compare API 660 and TEMA

Regards
r6155

 

[Christine74]

I don't think this is a vibration issue. More likely the wear you're seeing on the lead edge of the pass partition plate is caused by erosion from the flow bypassing due to excessive tube-side pressure drop. When the pass partition plate deflects the attachment welds crack.


-Christine

 

[Christine74]

That said, below is a link to a write-up of a repair performed to pass partition plate whose attachment welds cracked due to vibration:

http://www.wmsym.org/archives/2014/papers/14006.pdf

-Christine

 

[r6155]

KevinNZ
Please, can you tell us more information?: materials, shell diameter, thickness of shell and pass partition plate, fillet weld, ......

Regards
r6155

 

[SnTMan]

...pressure drop across the plate?

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[KevinNZ]

Thanks for your replies.

In this case there seems to be a combinations of things that can be better

Use a full weld and not two fillets.
Better fit of the plate into the groove on the tube sheet.
Support the plate.