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(Note) Repair works marked by * are conducted by Iwaki.
Trouble
Causes
Countermeasures
Inspection and check points
Discharge
volume is
reduced.
Supply air pressure or air
volume is reduced.
q
Set back to initial set
value or review air
flow rate.
a Secure a diameter and air flow rate in
consideration of the number of
pumps installed.
Increased discharge pressure
w
Review discharge
conditions.
a Check filter for clogging or dry-up.
b Check if air is removed from the
filter well.
c Check if discharge-side valve is open.
Valve is clogged with
foreign matter.
Wear of valve or valve seat
q
Replace pump head.*
a Install pump guard filter or the like
on pump suction pipe.
Insufficient NPSHa
(Netpositve suction hcad
auailabk)
q
Check suction
conditions.
a Check if suction pipe is too narrow
long.
Liquid leaks.
Stud bolt is insufficiently
clamped.
q
Replace pump head.*
Tight stud bolt with rated torque.
(Keep record of tightening torque for
next periodical inspection.)
Bellows are damaged.
a Check if supply air pressure is lower
than the specification.
b Check if pump stroke speed is lower
than the specification.
c Check if liquid temperature is lower
than the specification.
d Check if residual pressure is
removed upon pump stop.
e Check if air pipe is narrow and long.
f Check if suction pipe is narrowed.
Excessive air
consumption
Wear of shaft packing
Replace packing.*
Pump function
is not balanced.
Wear of valve or valve seat
q
Replace pump head.*
Excessive
vibration or
noise
Pump is not fixed on the
equipment properly.
Tighten anchor bolt.
q
Set pump stroke
speed lower than the
specification.
a Lower supply air pressure or reduce
air flow.
Faulty selection of
electromagnetic valve
q
Inspect and repair or
replace.
a Set pressure higher than min.
operation pressure for
electromagnetic valve.
Pump stroke speed is
excessively high.
