Heat exchanger materials of construction

[blackweta]

Hi. What is the most reliable shell and tube material to suit a tube pass temperature of 540 deg C and 1900Kpa H2 gas.
Shell temp is around 440 deg C and 1040Kpa process Steam. [ unit is SMR]

Please review attachment. Assuming it is visable.
Thanks

 

[srfish]

Is there any H2S or other corrosive elements in the gas ?

 

[MJCronin]

black...

Where will this replacement unit be located ?

-MJC

 

[roker]

hello,

see API 571

Regards,
roker

 

[blackweta]

SRFISH. No H2s this is a very clean gas stream. Sometimes we have some steam condensate through the system on early start up. We only have about 4 to 6 cycles per year max.
Where is the unit located does that make a difference?.
All our equipment is ASME and only API for some storage tanks.
Thanks

 

[srfish]

Hello,

I am not a materials specialist but have some observations due to spending years in the heat exchanger industry. I know the A 106 material in the shell is not good enough for this service at these temperatures and pressures. The minimum is C-1/2 MO. The tube side minimum is 1 1/4cr-1/2 MO.

 

[blackweta]

Thanks. The material I am thinking would be appropriate is SA 387. Can you be a bit clearer on your materials description. I guess Your indication is these materials are a grade of Sa ???.
Do you agree Incaloy 800 H would definately be an over spec for my temps and pressures. We have past experience with cracks in heat affected zones on the Incaloy. Its imperative that good PWHT is conducted after any fabrication work.

 

[SJones]

Sorry if I'm a bit lost, but shouldn't API 941 be a strong contender for guidance here?

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdoweb/

 

[srfish]

Hello,

I believe SA-387 could be used for the tube side if it is at least a grade 11. The shell side alloys couild be SA-204 plate or SA-335 P1 pipe,

 

[blackweta]

Cheers chaps I will check out your thoughts.
BW