Fuel Tank Vacuum-Relief Valves

One-way valves allow air to be drawn into the fuel tank, assisting flow and preventing implosion, but do not allow fuel vapour to be released.

Push-fit hoses allow valves to be connected to a spur-pipe, with inlet usually between body panels or other convenient location.

Valves normally contain a steel ball, but with a nylon ball they operate without fuel leakage at an angle of 90° to horizontal. Material is acetal.