A fluid flow metering device comprises a ball valve locatable in a fluid flow, there being at least two transverse bores through the ball valve, being a first transverse bore and a second transverse bore. The first transverse bore includes a fluid flow metering apparatus for measuring the rate of fluid flow through the first transverse bore, the ball valve being rotatable between a first metering position where fluid is flowable through the first transverse bore and a second open position where fluid is flowable through the second transverse bore, and the second transverse bore being dimensioned so that a tool is movable through the second transverse bore when the ball valve is in the second open position.