RATIO CHECK PROCEDURE
60089-05
Page 8
The following is the list of items to check if the equipment is not dispensing the correct ratio. Please note that some items
included in this procedure are not included with all supplied equipment. Please use all safety devices such as but not limited to
gloves and eye protection. When working with solvents do so in a well-ventilated area free of combustible items. Take every
effort not to mar or damage any surfaces that come in contact with materials.
If you suspect the ratio is incorrect and the dispense valve is in good condition, proceed as follows:
Remove retainer cap and/or mixer nozzle.
Trigger applicator; two separate beads of material will appear. Dispense each bead into separate cups; compare for correct
volume.
o
If ratio is incorrect with mixer off, proceed to Step 3
o
If ratio is correct with mixer off, perform additional test to verify results. If ratio is correct again with mixer off, the most
common cause is the metering pumps are worn & need replacement or refurbishing. Contact AST if this occurs.
If volume is off from Step 2, remove hoses from dispense valve, trigger applicator & dispense each material into separate
cups. Compare volume of material dispensed out of material hoses.
o
If ratio is correct, the problem is occurring in the dispense valve. Clean and/or replace seals,
O-rings & packings, if necessary.
o
If ratio is incorrect, proceed to Step 4.
If volume is off from Step 3, remove hoses at the outlet assembly. Trigger applicator and dispense each material into
separate cups. Compare volume of material dispensed out of outlet assembly.
o
If ratio is correct, the problem is occurring in the material hoses. Clean and/or replace hoses.
o
If ratio is incorrect, proceed to Step 5.
If volume is still off from Step 4, disassemble & clean pumps. Replace seals & O-rings if necessary.
Other items of note:
Verify that the air inlet to the tank is in good condition. The air goes into the tank through the 90 degree elbow.
Check for blockages on the inlet side of the pump with the reduced output. The round inlet block will have to be taken off
the back of the pump. Then, inspect the piping leading from the tank to the inlet block. If a blockage is found, it may not be
necessary to go any farther.
Clean and rebuild the pump. Check that the inner and outer gears are tight against each other. [Note: be careful not to
damage the inner pump parts when disassembling or cleaning. Replacement parts for the gerotors are available only as a
complete pump!] *Remove all crystallized or partially hardened material from all surfaces that contact the material.
Check the pump outlet fitting. (The elbow fitting between the pumps and the hoses) for blockages.
**NOTE: Any material that is left in the machine that is partially or completely hardened, or foreign objects, will
eventually cause a problem somewhere and should never be left in the pump**
