Protectoseal Series No. 830, Pressure / Vacuum Conservation Vent with Flame Arrester, is designed to prevent costly evaporation losses, tank rupture due to over-pressure, and collapse due to vacuum. The flame arrester protects tank against fire and explosion caused by exterior sources of ignition. Pallets in the vent housing minimize air and vapor loss as the tank "breathes". They open and close just enough to maintain safe working pressures and avoid damage to the tank. The flame arrester is mounted externally and is only exposed to vapors when venting.

Suitable for Group D Vapors, such as gasoline and methane, as referenced in the National Electric Code (NEC Article 500), generally equivalent to International Electrotechnical Commission (IEC) Group IIA.