Key Containment Strategies

Transformer Firewall
A transformer firewall serves as a fire containment barrier between one oil-filled transformer and other neighboring transformers, building structures, and site equipment. Effective transformer firewalls must be made from materials that can withstand the intense heat and long duration of transformer oil fires. They must also be designed such that both thermal and mechanical requirements are met before, during, and after the fire.

Installed modular refractory concrete firewall Photo courtesy of Oldcastle Precast Inc.

 

Projectile Blast Barrier
A projectile blast barrier having sufficient impact resistance to survive shrapnel impingement is also essential to protecting nearby assets. Fire caused by transformer failure may initiate an explosion, blasting projectiles such as steel fragments and porcelain up to 250 feet or more into the surrounding areas. Such projectiles have been found embedded into transformers, equipment and office walls in nearby buildings. As there are yet no standards for firewall impact loading, experts in the fields of ballistics and explosives have recommended applying UL Standard 752. This is equivalent to a firewall panel stopping a .44 magnum projectile with no through-penetration.

Refractory concrete ballistics test Photo courtesy of Alonso Rodriguez