Model FF-1600 with out Heat
20
17942C-1, Issue 1
Inlet Filter Screen
A filter screen in each Proportioning Pump filters out solid matter that could adversely
effect the operation of the valve balls in the pump base. You will note that the Daily
Start-up Procedure indicates these screens should be inspected daily.
For the first week or so of operation, you should clean both pump screens on a daily basis.
However, you will probably find that the resin pump screen remains clean and that weekly
checking of this part will be sufficient.
The Isocyanate pump screen is another matter. The Isocyanate component can crystallize
from either moisture contamination or from freezing. If you follow proper storage,
transfer, and operating procedures, and if the chemicals you receive, are clean, you should
have little problem with the Isocyanate screen. In practice though, findings suggest that
daily cleaning of the Isocyanate screen is sound preventative maintenance. It is important
not to clean the Isocyanate pump screen during the shutdown operation. This is because
the cleaning of the screen exposes it and its related parts to moisture and solvent, which
can cause the Isocyanate to crystallize. By accomplishing the cleaning operation during
the Start-up Procedure, contamination problems will flush out immediately when
dispensing commences.
Removal and cleaning of the filter screen is accomplished as follows:
1.
Switch OFF the Pump Switch and disconnect air from the Proportioning Unit. Bleed
chemical pressure from the side you are working on by opening the corresponding
manual valve on the coupling block while pointing it into an appropriate container.
2.
Close the material supply valve at the inlet of the appropriate Proportioning Pump.
This prevents the pumping of material with the screen screw removed.
3.
Place a cup, in the space provided beneath the filter base to catch the chemical, which
will drain-off upon removing the screen screw.
4.
Loosen the screen screw sufficiently to allow the material in the screen screw cavity
to drain out into the cup.
Remove the screen screw from the pump base by continuing to unthread it until it
comes loose.
5.
Remove the retainer ring at the end of the screen screw and slide the screen from the
screen screw. Thoroughly flush the screen screw, the retainer ring, and the screen
with the gun cleaner, and shake them dry. Inspect the screen to insure the mesh is not
restricted. Replace as required.
6.
Slide the screen on the screen screw and replace the retainer ring.
7.
Flush the cavity in the pump base with gun cleaner and wipe the cavity clean using
caution not to push foreign matter into the ball seat.
8.
Install the screen screw assembly into the pump base by inserting the screen screw
with the threaded portion sliding along the top cavity. This prevents pushing foreign
matter into the ball seats.
9.
Open the material supply valve; insure there are no leaks and wipe the equipment
clean.
