API 650 - SHELL NOZZLE & ROOF NOZZLE

[MOHAMMED89]

Dear Friends,

I have one doubt regarding the API 650 Shell Nozzle.

We already fabricated 16" Shell nozzle for API 650 Storage tank but not yet fixed on the shell, The Schedule considered for this nozzle is XS. My question is now we want to install this nozzle on the roof of the tank, Tank height is 20m, Rafter supported fixed cone roof with 6mm Plate Thickness. Is it possible to install this fabricated 16" shell nozzle to Roof, Please let me know you advises.

Thanks in Advance

 

[IFRs]

A shell nozzle will exceed all API requirements for roof nozzles. The repad may have to be flattened out, but I see no reason to not use it on the roof. If there is piping to be attached to this nozzle, support the piping to keep the nozzle loads essentially zero.

 

[MJCronin]

Mo....

Please explain the function of this large nozzle and why that it must be placed on the roof of this API-650 tank.

Will there be some type of removable heat exchanger inserted in this nozzle ?

Aside from a manway, vent and "thief hatch" I do not understand why shell (or bottom) nozzles would be acceptable for all services.

Is this the way that the nozzle is shown in the PIDs ??


MJCronin
Sr. Process Engineer

 

[MOHAMMED89]

Dear Friends,

Thanks for your reply.

Actually what happened is that , As per the old P&ID the size of the shell nozzle is 16", now its revised to smaller size. But we already fabricated the 16" Nozzle but not yet installed on the shell. and 16" Sampling nozzle required in roof. I know for roof nozzles above 12" will fabricate using 6mm thk plate. But in our case we don't to waste that 16" nozzle(Already fabricated), Roof type is Rafter Supported roof But plate thickness is only 6mm.

i think now you got the actual scenario, Please advice.

Thanks in Advance.