Protectoseal Series No. 7800 Emergency Pressure Vents are designed to provide emergency relief capacity beyond that furnished by the operating vent on tanks. The Series No. 7800 vents do not provide vacuum relief. Vacuum relief must be supplied by independent operating vents (See Protectoseal Series No. 830, Series No. 8540H, Series No. 6240, Series No. 18540 or Series No. 16240).
Under normal operating conditions, the vent pallet assembly is closed providing an effective vapor seal. In the event of an emergency (fire involvement of the tank), the pallet lifts in response to the increased pressure in the tank's vapor space. Vapor is expelled, thereby protecting the tank from dangerous over-pressurization. Pallet assembly automatically closes and reseals when the pressure is reduced.