SA 387 Gr.11 Cl.2+SA 240 TP.347 CLAD 1

[etsen]

The shell material of a heat exchanger is SA 387 Gr.11 Cl.2+SA 240 TP.347 CLAD. But I can't understand what SA 387 Gr.11 Cl.2+SA 240 TP.347 CLAD means. So can anyone explain it? Thanks a lot.

 

[jehan17718]

etsen,

It means that the base metal is SA 387 Gr11 Cl.2 (a low alloy steel) with a SA 240 Gr 347 (austenitic stainless steel) cladding.
The cladding will be in contact with the fluid. Assuming that disbonding ndoes not occur, the base metal will thus never be "wetted" with the process fluid.
Although CODE allows, the cladding is NOT considered to contribute to the mechanical strength as per good engineering practice. Thus, in all your mechanical calculations only consider the thickness of the base metal; which in this case is SA 387 Gr11 Cl.2
Hope this helps.
-jehan

 

[vesselfab]

layer of 1.25CR/.5Mo steel for your pressure containing shell with a thin layer,usually .1 min/.125 nom thick, of 347 stainless steel bonded to it for corrosion protection.
it can be roll bonded where the 2 layers are bonded together through heat and pressure bonding by rolling or by means of explosion bonding.

You should also look up in ASME code rules for clad plates and the NDE associated with them.

 

[weldtek]

Or by weld overlay.