Introduction. At the moment for extinguishing oil and petroleum products in vertical steel tanks widely used air-mechanical foam. The main reason for its poor performance is the inability to isolate the source of fire on the environment. This red-hot tank walls are a good source to ignite heated vapors of a flammable liquid that spread quickly through the crumbling foam layer. The use of carbon dioxide to extinguish a vertical steel tanks is a new, highly effective. The main prevailing differences of this installation are the response time and integrated quenching method - simultaneous exclusion oxidizer and an ignition source (hot tank walls). Supplying foam solution tank time is approximately 5 minutes after the operation of the ignition signal, and carbon dioxide fills the interior of the tank in 30 seconds. Description of experimental studies. The efficiency of the installation of gas fire extinguishing based on isothermal with carbon dioxide module is confirmed by field trials. Tests were conducted on a model of the vertical tank RVS-1000 10 m in diameter. The mixture was used as fuel oil (99 % by weight of oil) and gasoline (up to 1 % by weight). Estimated number of gas extinguishing agent is 1021 kg. Tests were carried out in three stages: the main issue of the calculated amount of extinguishing agent; release of a reserve stock of the fire extinguishing agent 15 minutes after the second planned arson former oil composition; the use of stock to cope with the extinguishing agent after the smuggled from mobile isothermal containers while maximizing the free burning time. Results and conclusions. Permanent installation of gas fire extinguishing module based on isothermal with carbon dioxide has proven effective for fire suppression vertical steel tanks with oil and oil products. Fire suppression time is less than 60 seconds. Upper accommodation efficiency of the distribution manifold as compared to the lower placing is confirmed. Besides, simultaneously with fire extinguishing it’s occurred efficient cooling of tank walls that previously could not be achieved by other systems. A significant result of the experiment is also a high performance fire-fighting technology using additional reserve amount of extinguishing agent after the first start-up and the ability to recharge from the mobile isothermal containers.