The BTG Basis Weight Valve is designed for precision control of the pulp flow to the paper machine. It is distinguished by its extremely high accuracy and resolution in process conditions. The linear characteristic of the valve makes it ideal for precision control. The design has proven to be extremely reliable in numerous installations worldwide. The valve is either a ball segment valve from Somas, or a ball section valve from MKE, that is ideal for accurate flow control over the whole valve stroke.The design of the valves are based on well-known standard design but are adapted for the basis weight valve application. To control the valve an electric actuator driven by a synchronous motor is used. The motor is connected to the valve spindle through a highly accurate gearbox (Harmonic Drive). The standard actuating time is 260 seconds at 50 Hz and 217 seconds at 60 Hz. The valve and actuator are connected by a special arrangement to provide a backlash (play) and striction free transmission. The control unit (optional) controls the valve and displays the valve position in %. A precision potentiometer in the valve generates a signal that is transformed into a current signal (4 - 20 mA) before sending it to the control unit. This conversion makes it less sensitive to disturbances. This signal is not intended to be used as a feedback signal in the control circuit, only as an indication of the valve position. The valve can be directly controlled by a controller/computer making potentialfree closing contacts, or open collector with pulse duration output. Via a separate relay box, not provided by BTG, a SCR (thyristor-pulsed output) can be connected.