Maintenance
Tighten up dosing head bolts
34
Stepper motor-driven diaphragm dosing pump NXP-M and NXP-P
Operating instructions
12 Maintenance
Dosing pumps by Neptune are manufactured to the highest quality
standards and have a long service life. Nevertheless, some of their parts
are subject to wear due to operation (e.g. diaphragms, valve seats, valve
balls). This means that regular visual inspections are necessary to ensure
a long operating life. Regular maintenance will protect the dosing pump
from operation interruptions.
DANGER
Mortal danger from electric shock!
Live parts can inflict fatal injuries.
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Before carrying out any maintenance work, always disconnect the
dosing pump from the power supply.
ð
Secure the dosing pump from accidental power-up.
WARNING
Caustic burns or other burns through dosing media!
While working on the dosing head, valves and connections, you may
come into contact with dosing media.
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Use sufficient personal protective equipment.
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Rinse the dosing pump with a medium (e.g. water) which does not
pose any risk.
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Release pressure in hydraulic parts.
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Never look into open ends of plugged pipelines and valves.
WARNING
Caustic burns or other burns through dosing media!
After connecting the mains supply, residual dosing media in the
dosing head can spray out.
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Before connecting the mains supply, connect the dosing lines.
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Check that all the screw connections have been tightened
correctly and are leak-proof.
CAUTION
Danger of personal injury and material damage!
The dosing pump can generate a pressure that is many times the
rated one. The dosing medium can escape in the case of material
failure or wear on the dosing head, the connection pipe or the seals
that are used.
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Carry out maintenance work at the recommended intervals.
12.1 Maintenance intervals
This table gives you an overview of maintenance work and the intervals
at which you must carry it out. The next few sections contain instructions
for carrying out this work.
Maintenance work to be carried
out
Frequency
Check that piping is seated firmly
Regularly
Check that suction and discharge
valves are seated firmly
Regularly
Clean suction and discharge valves Regularly
Check that electrical connections
are not damaged
Regularly
Tighten up dosing head bolts
n
Regularly
n
Before initial commissioning
n
After each diaphragm
change
Check diaphragm for leakage due
to rupture
Regularly (as long as no leak
monitoring system is installed)
Check that the installed accesso-
ries are functioning correctly
Regularly
Check the dosing pump for unusual
noises during operation, unusual
temperatures or smells
Regularly
Replace parts that are subject to
wear (diaphragms, valves, seals,
etc.)
When unacceptable levels of
wear are detected
Rinse out and clean the dosing
pump
Before changing diaphragms
Before taking out of service for a
long period of time
After feeding aggressive, sticky,
crystallising or contaminated
liquids
Table 28: Maintenance information and maintenance intervals
12.2 Tighten up dosing head bolts
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Tighten the dosing head bolts in diagonally opposite sequence with a
torque wrench.
The necessary torque is 16 Ibf in.