Water requirement for PMG Tank in case of Tank on Fire

[Asad_326]

If 140 ft diameter PMG tank is on fire

i) If Tank is on Fire from inside and Foam will be poured into the tank using Foam Chambers
ii) If Tank is on Fire such that roof has been blown and product has been spilled outside and Foam will be poured to the tank using Foam Monitors

then do we only require to pour the foam for both cases or do we also require to cool the shell surface of the same tank by showering the water using hydrant or sprinkler system? Any reference of code to this is highly appreciated.

 

[UFT12]

Are these generalized questions or project specific? Insurers have a lot to say here and typically impose their own standards with analytical system implementation which must be strictly followed. Therefore, most likely you find your answers there.

Generally speaking, water applied on the outer shell by a deluge system is usually installed for cooling the non-fire (nearby) tanks so that incident radiation (depending on wind could also be convection) will not involve them in the fire situation. Therefore, typically you shouldn't involve this system as an additional means on the fire fighting scheme for the tank under fire.

There may be cases where this is desired but requires some good consideration. For example, can you rely on the deluge system if the tank is exploded or ruptured to some good extend? Also, what about clear water (non foam) comes in contact with the burning flammable liquid?

Further, there are reports which raise concerns about cooling the fire tank. It must be made evenly because sagging due to uneven temperatures can occur. This is especially true for hydrant systems (not talking about foam here) which are mainly used for cooling but by their nature their application is usually one-sided. But this is also depended on many other stuff like size of tank and above all what is burning.

Conclusion, read my first statement gain.