POLYURETHANE
MACHINERY
CORPORATION
PHDX-2 SERVICE MANUAL
12. TROUBLESHOOTING
12.3
METERING PUMP-LINE
Figure 17: Metering Pump-Line (PL-10)
Frequent Pump-Line Problems
Metering pumps do not change direction and the pressures on both of
chemical gauges are lower than normal.
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Pump Cavitation.
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Pressure Loss: Discharge/Inlet Ball.
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Follow the recommended procedure in the indicated order to solve the problem and avoid
unnecessary repairs. Make sure all features are in the correct setting before determining the
existence of a fault.
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Problem:
Metering pumps do not change direction and the pressures on both of
chemical gauges are lower than normal.
Solutions:
1. The Metering Pump Line has Reversing Plates which actuates two Proximity
Switches (EL-153), one at each end of the stroke. The Prox Switches in turn
actuate the appropriate Directional Valve Solenoid (HI-05003). Failure to make
contact with either Prox Switch may be caused by:
a. Deformation of the Reversing Plate.
b. Foreign material preventing the Reversing Plate from contacting the Prox
Switches.
2. Passing of the Reversing Plate beyond the Prox Switch may be caused by:
a. Failure of the Prox Switch and related components on the side of the over-run.
b. Failure of a component of the Directional Valve.
c. Mounting Plate (PU-07006) and/or Prox Switch is out of adjustment.
REVISION 1.1
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