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Maintenance
4. Troubleshooting
CAUTION
●
Before working on the pump disconnect the power cord, depressurize the discharge
tubing and drain or flush any residual liquid from the pump head and valves.
Problem
Possible Cause
Corrective Action
Pump does not start
- Faulty wiring
- Improper voltage
- Electronic control unit is damaged.
- Correct wiring
- Connect to proper voltage source
- Replace control unit
Pump does not prime
- Air in suction tubing
- Valve gasket is not installed
- Valve ass'y direction is wrong
- Pump is air locked
- Suction or discharge valve is clogged
with foreign matter
- Adhesion of valve onto valve seat
-
Reroute suction tubing to eliminate air trap
- Install valve gasket
- Reassemble valve ass'y
- Open air vent valve
- Disassemble, inspect, clean
- Disassemble, inspect, clean
Output
fl
uctuates
-
Suction or discharge valve is clogged
with foreign matter
- Air is trapped in pump
- Overfeeding
- Diaphragm is damaged
- Disassemble, inspect, clean
- Open air vent valve
-
Install injection valve or back pressure valve
- Replace diaphragm
Liquid leaks
- Fitting or coupling nut is loose
- Pump head is loose
- Diaphragm is damaged
- O ring or valve gasket missing
- Tighten
- Tighten pump head bolts
- Torque: 2.16N•m (B11•16•21, C16•21)
2.55N•m (B31, C31•36)
- Replace diaphragm
- Instal O ring or valve gasket
Check if the pump head mounting bolts are not loosened every 3 months. Tighten them
diagonally on the following tightening torques as necessary. The mounting bolts may
loosen during operation (An extent of looseness depends on operating condition.).
Torque
Torque
Parts name
ES-C31
2.55N • m
M4 hex. socket head bolts
ES-C36
2.55N • m
M5 hex. socket head bolts
ES-B11 • 16 • 21
2.16N • m
M4 hex. socket head bolts
ES-B31
2.55N • m
M4 hex. socket head bolts
ES-C16 • 21
2.16N • m
M4 hex. socket head bolts
Tightening torque of the pump head mounting screw
