Installations of Valmet Cooking Liquor Measurement


White liquor line

Retractable sluice mounted sensor is recommended in the minimum of DN200 WL line. 


Max. pressure

at 100 ºC/210 ºF: 15 bar / 220 psi

at 150 ºC/300 ºF: 10 bar / 150 psi

Max. pressure during withdrawal 5 bar (70 psi)


The sensor can be dismounted for maintenance while the process is running. 

Installation in a bend or straight section of the pipe. 


Recipes for clarified white liquor measurements 

Concentration range

Concentration unit

Temperature range

0-155 g/l

EA as NaOH

20 -150 °C

0-155 g/l

AA as NaOH

20 -150 °C

0-120 g/l

EA as Na2O

20 -150 °C

0-120 g/l

AA as Na2O

20 -150 °C

0-7,5 lb/ft3

AA as Na2O

68–302 °F

Valmet offers a calibration tool to fine tune the reading to match with the laboratory 


Installations to digester circulations

The sensors are installed in bypass line to allow maintenance while process is running. The chamber must be minimum of DN200 and Valmet recommends the pipes going into the chamber have a diameter of 80 mm  (3 “). In case of scaling issues the pipes need to be thermally insulated to minimize the need for maintenance. 





Sensor 4364


Sensor 4368


Recipes for black liquor measurements


Replacements and spare parts

The sensors and transmitters are interchangeable and require no extra calibration during replacement. The sensors are delivered readily calibrated so installation is only plug and play. If the TCU is replaced the calibration curve from the old TCU works just the same in new.