No flow meters, just psi gauges to do two things: 1) High side let's you know how much product is in the tanks 2) Secondary side let's you see how to adjust the pressures for the application...ie cutting, heating, welding, etc...
The devices are pressure regulators. They reduce and regulate the high cylinder pressure to the working / outlet pressure. The torch manufacturer's data sheet will show the flow rate and the consumption rate; at a certain outlet pressure for a certain torch nozzle or tip size.