Spiral Baffle inside jacketed vessel (Sec.VIII Div.1 Appendix 9) where to weld it to?

[pv_mkk]

What condition to decide where to weld spiral baffle (the thin plate to force direction of flow inside the gap between main shell and jacket) to outside of main shell side or to inside of jacket shell side?

I cannot find any book to support this. I saw some existing vessels in the same plant, some welded to outside of main shell side and some welded to inside of jacket shell side.

So i'm kinda curious. How do we decide?

Thanks for helping in advance.

 

[Dhurjati Sen]

Did you check the drawings?


DHURJATI SEN
Kolkata, India

 

[pv_mkk]

Yes sir,
I checked drawings and saw different design on several jacketed vessels.

So I just want to understand in which case we have to weld it to shell or in which case we have to weld it to jacket.

What I can think of is that most of jacketed vessels I've seen are made of CS jacket + SS main shell.

If we choose to weld spiral baffle to jacket then we can select CS plate that is cost saving. Instead of welding it to shell that you have to use SS plate. But still, I saw some designer that design SS spiral baffle welded to SS shell and I don't understand why.

 

[r6155]

The Spiral baffle welded to shell acts as an external pressure reinforcement ring.

Regards

 

[SnTMan]

I'd think it would largely be a matter of convenience in manufacturing.

Regards

Mike

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

 

[pv_mkk]

Dear r6155,

What if jacket design pressure is FV too?

Moreover, can we calculate the strength of spiral baffle (acts as reinforcement ring) the same way we do on typical reinforcement ring?

 

[pv_mkk]

Dear SnTMan,

Do you think there is anything to do about type of fluid in jacket such as hot oil, steam, cold water that affects on where we have to consider to weld spiral baffle to?

 

[r6155]

The spiral baffle welded to the shell also acts as a reinforcing ring for the jacket when FV is applied.

Regards

 

[SnTMan]

Offhand I'd say not, but who knows? Is the baffle 100% seal welded to the shell in that construction?

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