Heat Exchanger one stream out of service

[Whin]

The BFW preheater exchanger, featuring MP steam on the shell side, will be permanently decommissioned, while the tube side BFW will remain operational. The design pressure for the shell side is 24 Barg, whereas the tube side is rated at 88 Barg. The design temperatures are 390°C for the shell side and 182°C for the tube side. Is it necessary to adjust the shell side design rating to align with the tube side design pressure in the event of a tube failure?

 

[georgeverghese]

It is a process design error to set unequal design T for shellside and tubeside in this case. But now that steam is to be permanently disconnected, it probably doesnt matter.

A PSV on shellside set at 24barg is still required to cater for tube rupture failure.

 

[goutam_freelance]

A shell side relief valve is required to be operational to take care of the tube rupture condition. I hope this already exists.

 

[LittleInch]

"Is it necessary to adjust the shell side design rating to align with the tube side design pressure in the event of a tube failure?"

In theory yes, but not sure how you're going to suddenly increase the MAWP of the shell by a factor of 4.

Why not just substitute in a piece of pipe in place of the HX??

All your problems go away.