Patent ID: 7368001

Claim:
A tank installation for a volatile liquid wherein there is an ullage space above the liquid in the tank in which said ullage space vapour collects, said tank installation having a fill-pipe for the introduction of volatile liquid into the tank, said fill-pipe having an exit which is normally within said liquid in the tank, and a vapour recovery system for use during filling of the tank to recover vapour displaced from said ullage space, said vapour recovery system comprising: restriction means within the fill-pipe defining a region of the fill-pipe of reduced cross-sectional area whereby in-flow of liquid along the fill-pipe into the tank results in a reduced static pressure in said region; a duct extending from said region of reduced cross-sectional area through the fill-pipe to open into said ullage space above the liquid in the tank; and a normally-closed valve assembly associated with the duct which valve assembly normally closes off communication through the duct between said region of reduced cross-sectional area and said ullage space, said valve being opened by in-flow of liquid along the fill-pipe into the tank, such that vapour in the ullage space is drawn from the ullage space along the duct by the reduced static pressure in the region of reduced cross-sectional area of the fill-pipe.