On the lager taps, you may see a big round knob on the very front of the tap, that is the flow control. It may also be located behind the spout on the horizontal strut, that is more like a collar. That is flow control also.
The newer Guinness taps use the valve it's self for flow control, and the range adjustment for that is at the base of the handle.
Most industrial beer taps don't use the little lever that the homebrew and craft taps use, as they are too easy to knock around and mess up your settings.