H-20/35 VR Series Proportioning Unit
44
42942-VR-1, Issue 1
2. Place a container beneath the strainer base to catch the drain-off of chemical when
removing the strainer screw.
NOTE:
More than 25% restriction of the
screen can prevent proper filling
of the pump during operation. If
more than 25% is blocked, the
screen should be replaced.
Figure 23. Y Strainer Components
3. Remove the screen from the strainer base. Thoroughly flush the screen with gun
cleaner and shake it dry. Inspect the screen to ensure that no more than 25% of the
mesh is restricted. Inspect the strainer screw gasket and replace as required.
4. Install the strainer screw with the strainer in place and tighten. Important: Take care
not to over-tighten; let the gasket make the seal.
5. Open the material supply valve; ensure there are no leaks and wipe the equipment
clean.
6. Proceed with operation.
Pump Lube System
To ensure that the pump lube will do its job, check its condition on a daily basis. Change
the pump lube before it becomes a gel, or when its color becomes the same as the
Isocyanate.
The gel formation is due to moisture absorption by the pump lube. The time interval
between changes due to gel formation depends entirely upon the environment in which the
equipment is operating. The enclosed pump lube system in the H-20/35 VR minimizes
exposure to moisture, but moisture contamination is still possible.
Discoloration of the pump lube is inevitable due to the continual weepage of Isocyanate
during pump operation. However, if the packing within the Isocyanate pump is
functioning properly, pump lube replacement due to discoloration should not be more
frequent than 3 or 4-week intervals.
To change the Pump Lube proceed as follows:
1. Position the Isocyanate Proportioning Pump to the extreme right by jogging the
Pump Switch.
2. Lift the lube reservoir out of the bracket and remove the cap from the container.
Holding the Cap over a suitable container, remove the Check Valve and allow pump
lube to drain. Reattach the Check Valve to the inlet hose.
