Operating Manual
Maintenance
2/12/04
35
Remove the ball seat with the special tool provided and inspect it for nicks and
scratches. Replace as required.
4. Inspect the face of the gasket for damage and replace as required. Reassemble the
pump base.
Inlet Filter Screen
A filter screen in each proportioning pump traps solid matter that could adversely effect
the operation of the ball check valves in the pump base. Both screens should be
inspected daily and cleaned as required, as indicated in the Daily Start-up procedure.
The isocyanate component can crystallize from either moisture contamination or from
freezing. If the chemicals received are clean and if proper storage, transfer, and
operating procedures are followed, there should be minimal contamination of the
isocyanate screen. In practice though, it is good preventative maintenance to clean the
isocyanate screen daily.
IMPORTANT: Clean the isocyanate pump screen during the start-up procedure
only. This will minimize moisture contamination problems by immediately flushing
out any isocyanate residue at the start of the dispensing operation.
Remove and clean the filter screen as follows:
1. Switch OFF the pump switch and disconnect air from the proportioning unit. With
the gun removed, point the coupling block into an appropriate container, open the
corresponding manual valve of the side to be worked on and bleed chemical pressure
to ZERO.
2. Disconnect the transfer pump air supply and close the material inlet supply valve of
the appropriate proportioning pump. This prevents pumping of material with the
screen screw removed.
3. Place a rag beneath the filter base to catch the drain-off of chemical when removing
the screen screw.
4. Loosen the screen screw just enough to allow the material in the screen screw cavity
to drain out onto the rag.
5. Unthread the screen screw and remove it from the pump base.
6. 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 gun cleaner, and shake them dry. Inspect the screen to ensure the mesh is not
restricted. Replace as required.
7. Slide the screen on the screen screw and replace the retainer ring.
8. 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.
9. 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 foreign matter
from entering into the ball seats. Thread the screen screw securely into the pump
base.
10. Reconnect the transfer pump air supply and open the material inlet supply valve.
Ensure there are no leaks and wipe the equipment clean.
