Multi-layer diaphragm pump
Serie 409.2 ML
Operating instruction
TA 431
Rev.
8 en
06/2015
Technical modifications reserved!
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33
Fault analysis and corrective action
Type of fault
Possible cause of problem
Rectifiying the problem
P
um
p
do
es
not
pr
im
e
P
um
p
do
es
not
d
el
iv
er
C
apa
c
it
y
not
at
tai
n
ed
D
el
iv
e
ry
p
res
s
ur
e not
r
e
ac
h
ed
C
apa
c
it
y
f
luc
tuat
es
C
apa
c
it
y
gr
e
at
er
t
ha
n s
pec
if
ied
M
ot
or
do
es
n
ot
s
ta
rt
T
o
o m
uc
h
v
ib
rat
ion i
n pi
pi
n
g
P
um
p
t
o
o n
oi
s
y
S
er
v
ic
e l
if
e
of
w
or
k
ing
di
aph
ra
gm
s
t
oo
s
hor
t
M
ot
or
i
s
ov
er
load
ed
D
am
ag
e t
o
s
tr
ok
e
m
ec
h
ani
s
m
/
dr
iv
e
Lea
k
s
a
t p
um
ph
ead
Suction height too great
Reduce suction height or suction resistance
Suction connection not tight
Check pipe seals and tighten connections
Closed shut-off valve in pipe
Open shut-off valves resp. check opening status – dismount
pump and check on poss. damages. replace damaged parts
No liquid in dsing tank
Fill supply tank
Pump valves leaking
Remove and clean pump valves
Pump valves (valve seats) damaged
Remove pump valves – check replace if necessary
Valves wrongly mounted or valve ball
missing
Check against sectional drawing to ensure correct assembly.
Replace or refit faulty parts
Filter in suction pipe clogged
Clean suction filter
Electrical data of the drive motor do
not comply with the network
Check order data. Check electrical installation.
Adjust motor to the network on site
Delivery pressure too high
Check pressure directly above pressure valve with manometer
and compare order data resp. with perm. counterpressure
Foreign bodies in valves
Remove pump valves and clean
Delivery on suction side is greater than
pressure at the end of delivery line
Check geodesic conditions and insert float valve or pressure
retaining valve.
Velocity too high owing to geometry of
pipework
With a pressure gauge check the velocity on the suction and
pressure side of the pump. Compare with order data. If
necessary fit pulsation damper
Contact materials not resistant and
unsuitable
Check medium against original order and quote. If necessary
select different wetted parts
Viscosity too high
Check viscosity and compare with order confirmation. If
necessary reduce concentration and/or raise temperature
Medium gasses off in suction line
Check geodesic conditions (pipework layout). Increase suction
pressure and/or reduce temperature of medium.
Air in suction pipe whilst pressure is
present in delivery line
Ventilate pressure side or open vent valve (only with FRP-
execution, see chapter 6.6)
Pipe connection leaking
Retighten connections according to the type of material. Take
care with plastic parts and do not fracture.
Temperature too low
Check flowability of the dosing medium. Temperature of
the medium may not be lower than –10°C
Medium frozen in pipe
Dismount pump from system and check for damages – raise
temperature
Diaphragm rupture
Replace the diaphragm according to the descriptions in
Chapter 10.4
Air between the diaphragm layers
Remove the air between the diaphragm layers
Tab. 07 (Fault analysis and corrective action)