Abstract: A flow meter is disclosed which is securable to the butt end of a pipe such as a filler tube for domestic fuel oil tanks. The meter comprises a housing which is threadably securable to the butt end of a pipe through a first opening in the housing. A transverse opening is provided in the housing for the insertion of a flow meter through the first opening and a U-shaped cutout in the pipe to which the housing is threadably secured. A door is provided over the top of the housing and the first opening, the door being lockable to the housing so that the meter and housing may not be unscrewed from the pipe, the door also comprising a lockable cap over the butt end of the pipe.