20
8. MAINTENANCE
8.1 ROUTINE MAINTENANCE
Under normal conditions the
ViscoSense
®
3
interface box requires no maintenance.
“Normal” means;
A clean operating environment
ViscoSense
®
3
interface box installed in accordance with the installation instructions given.
Operation of the
ViscoSense
®
3
interface box and related control system in accordance with this
manual and other related publications
Uninterrupted power supply at normal specified values.
8.2 TO CLEAN THE
VISCOSENSE
®
3
SENSOR
When removing a
ViscoSense
®
3
sensor from the piping system precautions must be
taken to prevent personal injuries and damage to the sensor and process installation.
See chapter 15.1.
8.2.1 General procedure
1. Change over to manual viscosity control.
2. Shut off the flow through the
ViscoSense
®
3
sensor, by closing the valves on both side of the
sensor housing.
3. Switch off power supply to the
ViscoSense
®
3
interface box.
4. If possible drain and empty the piping system.
Although the flow has been shut off, the
ViscoSense
®
3
housing can still be under
pressure and hot. If the sensor is removed from a sensor housing which has not been
de-pressurized, hot oil will spray out.
5. Unscrew the
ViscoSense
®
3
sensor from its housing by loosening nut 1 (Figure 8
ViscoSense
®
3
sensor assembly).
6. Take out the
ViscoSense
®
3
sensor.
7. Do not remove the flow tube, do not stick any object in between the flow tube and pendulum.
8. Flush the space between the tube and the pendulum with diesel oil or non aggressive cleaning
detergent.
Take care that the pendulum is not damaged or the torsion tube bent by mechanical
force.
NEVER use abrasive materials like sandpaper, files etc., to clean the flow tube.
