Design of floating head ( S type )

[Dinesh2600]

Hello all,

I'm currently design a BES type heat exchanger in PVElite with ID of 800 mm and 23 bars design pressure at shell and tube side at 240 deg C and I am not sure on how to design the floating head part. I have listed my queries in below points.

1. Should the ID of channel part of floating head be more than the main shell. Because that's how the diagram is shown in TEMA table. If yes by how much.

2. Should the floating tube sheet be extended as flange or the bolting will be backing ring and floating head flange.

3. Are the dimensions of floating head tube sheet flange and backing device an iterative procedure or relations are given anywhere in code ?

 

[Christine74]

When you say "ID of the channel part" I'm assuming that you're referring to the shell cover. For a TEMA "S" exchanger the diameter of the shell cover has to be a bit larger in order to accommodate the floating head cover and the backing device, which are both necessarily larger in diameter than the shell ID.

The floating tubesheet for an "S" exchanger does not have an extended flange, as this would increase the required diameter of the shell and thereby defeat the purpose of using an "S" exchanger.

ASME has rules for designing floating head flanges and TEMA has guidelines for designing the backing device. It's an iterative process.


-Christine