Basis weight control is a critical part of paper machine operation. The base weight Valve, installed in the stock preparation department in front of the paper machine, as Shown below, controls the consistency of the pulp into the head box, dictating the paper. Weight and quality at the end of the process. The valve is controlled by a control signal. Showing the difference between the measured basis weight of the sheet on the reel at The end of the paper machine and the set point. Too high a measured basis weight Causes the valve to close to lower the consistency in the system while being too light. Makes the valve open to increase the consistency before the head box.