2 replies to this topic

[ChemEng01]

Hey Guys

 

I am looking at a seal oil shell and tube heat exchanger. (Shell side oil / Tubeside water)

 

Operating pressure of shell side (seal oil) is 100 barg. 

 

The design pressure of the tube side (water) is 10 barg

 

As the tube side with design pressure of 10 barg is in contact with the shell side fluid at 100 barg I presume that the external design pressure (or collapse pressure) of the tubes must be much higher than the internal design pressure. (over 10x higher)

 

Is there any guidelines or advice on this subject?

 

cheers

[Zauberberg]

You should consider changing sides of the hot and cold fluids and place seal oil on the tube side. It is far more cheaper to design tubes for 100 barg, than to have the exchanger shell designed for the same pressure.

[ChemEng01]

Thanks Zauberberg

 

This is a 30 year old exchanger I'm looking at though. Obviously it's doing OK because nothing has happened in 30 years.

 

I just thought it seemed wierd to have tubes with a design  pressure of 10 barg in contact with 100 barg oil on the shell side. The tube collapse pressure must be over 10 times that of the internal design pressure.

 

Cheers.