Operation
Commissioning the dosing pump
30
Stepper motor-driven diaphragm dosing pump NXP-M and NXP-P
Operating instructions
11 Operation
WARNING
Caustic burns or other burns through dosing media!
After connecting the mains supply, residual dosing media in the
dosing head can spray out.
ð
Before connecting the mains supply, connect the dosing lines.
ð
Check that all the screw connections have been tightened
correctly and are leak-proof.
CAUTION
Danger of automatic start up!
The dosing pump does not have an ON/OFF switch and may start to
pump as soon as it is connected to the mains supply. This means that
dosing medium can escape. Depending on the type and hazardous-
ness of the dosing medium, this can result in injury.
ð
Stop the dosing pump before disconnecting it from the mains
supply.
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Ensure that the dosing pump has been installed correctly before
connecting it to the mains supply.
11.1 Commissioning the dosing pump
Precondition for action:
ü
The dosing pump has been assembled and installed in accordance
with chapter 7 “Installing the Dosing Pump“ on page 17, chapter 8
“Hydraulic installations“ on page 18 and chapter 9 “Electrical
installation“ on page 24.
ü
All the mechanical fastenings have been inspected to ensure
adequate load-bearing capacity.
ü
The dosing head screws have been tightened with the correct torque
(see chapter 12.2 “Tighten up dosing head bolts“ on page 34).
ü
All the hydraulic sections have been inspected to ensure they are
adequately leak-proof and that the through flow direction is correct.
i
For initial commissioning, it is advisable to use water as the
dosing medium to check that the system is leak-proof and that
the dosing pump is functioning correctly. Check first whether
undesirable reactions could occur between the actual dosing
medium and the water.
Perform the following working steps:
1.
Open the shut-off valves on the suction and discharge sides if
present.
2.
Plug in the dosing pump's mains plug to the power supply.
3.
If the dosing head is fitted with a vent screw, vent the dosing pump
(see section 11.1.1 “Venting the dosing pump“ on page 30).
4.
NXP-M: Turn the stroke frequency setting slowly counter-clockwise
until the dosing pump draws in enough and dosing starts.
NXP-P: Select an operating mode and start the dosing pump in
accordance with the instructions in the chapter 11.2 “NXP-P:
Operating modes“ on page 31.
4
The dosing pump primes. If it does not prime enough, use a priming
aid (see chapter 8.7.6 “Priming aid“ on page 22).
i
At initial commissioning, it is advisable to prime the pump
without backpressure. For this purpose, we recommend
installing a relief valve on the discharge side of the dosing
pump.
ü
The dosing pump is commissioned.
11.1.1 Venting the dosing pump
Size NXP-M/P 68, 140, 285 plastic dosing heads are fitted with a vent
screw. Gas bubbles can be removed from the dosing head using vent
screws, in order to improve the performance of the pumps / to remedy
faults.
CAUTION
Danger of personal injury and material damage!
Dosing medium can escape if you loosen connections on the dosing
head (e.g. for venting) during operation.
ð
Use sufficient personal protective equipment.
ð
Follow the safety data sheet of the dosing medium.
ð
Clean the dosing pump if dosing medium escapes.
ð
Dispose of the dosing medium correctly.
Fig. 28: Dosing head venting facility with vent screw
Precondition for action:
ü
The dosing head venting facility connected has been connected in
accordance with the chapter 8.6 “Connecting the dosing head
venting facility“ on page 21.