Protectoseal Series 20, 1” Pilot Operated Tank Blanketing Valve is designed to regulate the flow of a blanketing gas (usually Nitrogen) into the vapor space of a flammable liquids storage tank. The valve senses the pressure in the vapor space and opens fully when the tank pressure equals the valve’s set point to allow a flow of gas into the tank. When tank pressure returns to near the valve’s set point the flow of gas is stopped. Each unit consists of a main valve which controls the flow of inert gas into the tank, and the pilot valve which accurately senses the tank’s pressure and controls the opening and closing of the main valve. Datasheet