PAPER PRODUCTION MACHINE

A paper production machine includes a sheet formation mechanism having a mixture chamber, a liquid flow line embodied to provide liquid flow to the mixture chamber, a valve for controlling liquid passage in the liquid flow line, and a control unit configured to provide controlling of the valve. The cellulose and liquid mixture, which is needed for production of the wet paper sheet, is kept in the mixture chamber. Accordingly, at least one pressure sensor is provided for measuring the liquid pressure in the mixture chamber. The pressure sensor is configured to transfer the pressure measurements to the control unit, and the control unit is configured to turn off the valve in case it is detected that the pressure measurements received from the pressure sensor exceeds at least one predetermined reference value.