Vapor space pressure control system for underground gasoline storage tank

摘要

A method for controlling pressure in the vapor or ullage space of an underground storage tank of volatile liquid fuel includes treatment or conditioning of gaseous flow of vapor and air and/or air into the ullage space in a manner to increase the fuel vapor concentration of the gaseous flow toward saturation. A system for controlling pressure in the vapor or ullage space of an underground storage tank of volatile liquid fuel is also described.