Design of Fire protection system for IFR tanks 2

[prashanth5723]

Hi
In the case of an IFR tank especially the one with Aluminum Pontoon IFR the fire protection is designed considering the entire liquid surface as done in a normal cone roof tank.

What happens to IFR in an event of a small fire in the tank and the foam is sprayed inside the tank. Will the IFR withstand and function as normal after the fire is put off?

Normally in case of steel IFR’s foam is poured on the IFR and tested when the tank is empty before the tank is put in operation. Is this possible with Aluminum IFR? Will the Aluminum IFR not get damaged? Can you advise me the correct procedure?

 

[IFRs]

As you know,a tank with a non-contact aluminum IFR is treated as a fixed roof tank, NFPA expects the floating roof to contribute nothing to the situation. You must have a foam system designed to fight a full-surface fire. There is no reason or procedure to test the IFR for its capacity to support a load of foam around the outer edge as if you designed for a rim fire. Also, many foams are ( or were ) corrosive to aluminum and testing would be self-defeating for that reason.

That said, some aluminum full-contact IFRs are quite stout and would likely survive a rim fire long enough to contain foam poured around the edge. It is not unheard of to include a (non NFPA) foam dam on an aluminum IFR to hedge your bets that the fire would be around the rim and for your facility tho have a chance at minimizing the loss. HFPA lists only one of these types (full-contact metallic sandwich panel) as suitable for a rim fire protection system, others may be also suitable but are not listed. Though listed in NFPA I don't think testing one with foam is recommended by the manufacturer.

My opinion only - beware of what you find on the internet!

 

[prashanth5723]

@IFR's. Thank you for the reply.
In the event of fire accidents in a pontoon type IFRVT, the foam pourer will be operated to suppress the fire. In that case what will be the impact of foam as well as the fire on the Al. internal floating roof? If the fire is put off in the initial stage itself, will there be any damage to the IFR? Also can you pls tell me the section of NFPA where the fire protection system details are given for a fixed roof tank? or can you pls send me any references for the fire protection system required for a fixed roof tank?