Abstract: To address the leakage issue of mechanical seal breather valves on nitrogen-sealed tanks in benzene-related tank farms, a petrochemical enterprise in central China applied a new type of liquid-sealed breather valve produced by a domestic manufacturer. This paper evaluates the application effect by comparing and analyzing the sealing forms, structural characteristics, and operating data of the new and old breather valves. The evaluation shows that compared with mechanical seal breather valves, the new liquid-sealed type has remarkable environmental and energy-saving effects in reducing tank VOCS (Volatile Organic Compounds) and nitrogen consumption of the nitrogen-sealing system, and realizes real-time monitoring of the breather valve's operating status. It effectively prevents the flash explosion risk caused by the accumulation of combustible gas on the tank top, providing an effective method for refining and chemical enterprises in the treatment of VOCS in tank farms.

Key words: nitrogen-sealed, breather value, leakage, VOCS, effectiveness analysis