Material for flue gas stack 3

[Rakesh2560]

I have to select material for isolating the boiler from stack (two boilers are connected to same stack we need one for maintenance) . I am not sure for which material to use for blind ?
Our planner has offered a283 gr8 c which is a structural steel grade when I referred as me sec 2 part d it prohibits it's use in sec1 design hence I cannot use it in boiler .second option is a516gr60 which is a better grade can I use it for design or need any specific material ?
Thanks in advance for all extended help

 

[Dhurjati Sen]

Hi Rakesh,

It is surprising that there is no provision of isolation given in the flue gas ducts of the boilers.

The selection of material for this 'temporary' blind depends on the duration of outage of one of the boilers. If you are not sure of the duration, go for any SS material (SS 304 would be fine). If the duration is around a month, any CS would do (even A283 Gr C).

 

[metengr]

I would not recommend nor do you need to use 304 stainless steel for this application. You are far better off using one of the low alloy steel plate materials, like SA 387 Grade 11 or Grade 22 for flue gas stack isolation.

 

[MJCronin]

Do you have any idea what the max temperature would be for the blank ? .... If less than 650F, carbon steel should be fine.

If higher, go with the recommendation of metengr ........ SS is not necessary.

MJCronin
Sr. Process Engineer