28
Troubleshooting
States
Possible causes
Solutions
No discharge
Air ingress
from:
gaseous liquid
Take measures to reduce gas.
a suction line (imperfect
joint or sealing)
Check for an imperfect joint/sealing and
retighten as necessary.
an empty tank
Refill the supply tank. Degassing is required
before resuming operation.
No discharge
from:
Clogged suction line or strainer Take apart and clean them.
Foreign matters in a check valve Take apart and clean the valve.
A damaged check valve
and valve seat
Replace with new ones.
A leak from:
a damaged diaphragm
Replace with new one.
Great pulsation
Reverse motor rotation.
Use an inverter or correct wiring.
A check valve and valve seat have been worn. Replace with new ones.
Foreign matters in the check valve
Take apart and clean the valve.
Suction line vibration is too big.
Support the suction lines.
Discharge pres-
sure is too low.
A check valve and valve seat have been worn. Replace with new ones.
Foreign matters in the check valve
Take apart and clean the valve.
Pressure gauge has failed.
Replace with new one.
Clogging in a pressure gauge
Remove clogging.
A relief valve is open.
Check/reset the set pressure.
Damaged diaphragm
Replace with new one.
Liquid leaks.
Overpressure (discharge line)
Inspect/solve the root cause of overpressure.
Damaged diaphragm
Replace with new one.
Damaged gaskets or O rings
Replace with new ones.
Misarranged valve assembly
Rebuild it in correct order.
Loose connection of the inlet and outlet
Tighten them as necessary.
Loose pump-head-fixing-bolts
Tighten them as necessary.
A noise level is too
high.
Motor failure
Replace with new one.
NPSHr is not satisfied.
Review the pump and piping system to
meet the NPSHr.
Damaged driven unit
Repair or replace with new one.
Overpressure (discharge line)
Inspect/solve the root cause of overpressure.
Oil level, grade or quality is wrong.
Check if it is proper. Replace as necessary.
Oil leaks.
Damaged gaskets or O rings
Replace with new ones.
No suction
A check valve and valve seat have been worn. Replace with new ones.
Foreign matters in the check valve
Take apart and clean the valve.
Clogged suction line or strainer
Take apart and clean them.
Air ingress from a suction line.
Check for loose connections and retighten
as necessary.
Damaged diaphragm
Replace with new one.
Damaged gaskets or O rings
Replace with new ones.
Entrained air in the pump head.
Perform degassing.
Misarranged valve assembly
Rebuild it in correct order.
Motor temperature
is too high (80ºC
or more).
Overpressure (discharge line)
Inspect/solve the root cause of overpressure.
Target frequency is too high or low.
Reset the dial to a proper position.
