BurkertFor gaseous-media applications, Burkert's Type 8750 Flow Rate Controller covers a broad spectrum of control applications, from DN15 up to DN100, including a control valve and two pressure transmitters. The complete system is mounted on a pipe with flange connection and is pre-wired. The pressure drop over the control valve, which acts as a restriction, is measured continuously by the two pressure sensors. This pressure difference and the valve flow characteristic are the parameters for determination of the volumetric flow through the control valve. This measured value is compared with the setpoint, evaluated in a PID controller and set on the positioner as the new setpoint.