salmson NEX, Инструкция по установке и эксплуатации

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ENGLISH
13
expansion at operating temperature. In pump installation involving high
liquid temperatures, alignment should be checked again when operating
temperature is reached (pump and piping). Alignment quality should be
checked just after machine shut down.
Pump and driver must be isolated electrically before alignment
operations are performed.
Pump and motor were aligned before dispatch. If it is necessary to
use very thick shims to adjust coupling alignment on site this
means that the baseplate is twisted. Leveling has to be modified.
Checking the coupling alignment :
Check distance between the two half couplings.
Check radial and axial deviation.
Several types of flexible couplings can be used. Refer to coupling
operating instructions to know adjustment values and
misalignment limits.
Several methods can be used to make coupling alignment. Choice of a
method will depend on the type of equipments available on site. Two
operating methods are briefly described hereafter. They can be used if
basic metrology equipments are available :
Using a straight-edge and a caliper :
Using a dial gauge :
When checking parallel alignment, the total indicator read-out
shown is twice the value of the actual shaft displacement.
Align in the vertical plane first, then horizontally by moving the motor.
Lifetime of ball bearing and coupling flexible part as well as pumpset
noise level will depend on the alignment quality.
Coupling alignment is not necessary when a IEC adaptation lantern is
used. Both motor and pumps shaft are aligned by construction.
7.2 PIPE WORK
7.2.1 GENERAL INFORMATION
Pump connection flanges are plugged to avoid any contamination during
transport and storage. Protective covers should be removed only before
installing the pump in the piping. Remove dust before removing the
covers from pump flanges. Especially for new pipe work : clean
thoroughly piping before connecting it to the pump.

Remove protective covers

Add flange gaskets

Fasten suction pipe

Fasten discharge pipe
No stress must be applied to the pump casing by the pipe work. If
excessive, those forces and moments cause misalignment,
overheating of bearings, coupling wear, vibrations and possible failure or
explosion of pump casing.
After replacement of a pump or during connection of pipes to
pump flanges, never use pump flanges as a support to pull or push
the pipe works.
The axial displacement of expansion coupling (if installed) should be
limited. Use tie rods as recommended by the manufacturer.
Two designs are possible for the suction line : positive suction head and
suction lift operation.
7.2.2 POSITIVE SUCTION HEAD INSTALLATION
Nominal diameter of the pipeline is often larger diameter than pump
suction flange. Unequal nominal diameter should be compensated by an
eccentric transition part. It is recommended to install a straight pipe
before the pump inlet (size L should be 2 to 3 times the pipe nominal
dimension). The suction line should be laid with a downward slope
toward the pump.
7.2.3 SUCTION LIFT INSTALL ATION
A dedicated suction pipe should be installed for each pump used with a
negative suction head (suction lift).
Nominal diameter of the suction pipe must be equal or a size larger than
the pump suction flange diameter. Pipe inlet should be set below lower
liquid level. Install a strainer with foot valve to prevent priming loss. The
strainer will be installed far enough from the pit bottom to avoid
excessive suction head losses and particles intake. Ensure there is no air
intake along the suction pipe and that the suction pipe is inclined up
towards the pump inlet. Avoid air pocket creation.
Suction lift line should be laid with a rising slope towards the pump. A
straight pipe (length should be 8 to 10 times the pipe nominal diameter)
should be added in front of pump. Nominal diameter of the pipeline is at
least equal to the pump inlet size. Pipe diameter is calculated to limit
flow speed to 2m/s.
The size of the suction strainer/foot valve will be selected to ensure
minimum pressure losses in strainer and full opening of NRV at pump
nominal flow.
Check that pump required NPSH (NPSH
R
) is lower than system
available NPSH (NPSH
A
).
2.1.1
ACCESSORIES AND PIPE S CONNECTION
Discharge pipe :
Nominal diameter of discharge pipe should be chosen to ensure a max
flow speed of 3m/s.
Filter :
If required a filter can be installed before the pump intake. To ensure
proper working of pump the equivalent exchange surface of the strainer
should be 3 time the pipe sectional area.
Clogging level of filter should be checked regularly.
Valves :
It is advised to install isolating valves on suction and discharge side for
maintenance purpose. Those valves should be of large passage type and
could be locked in position.
Isolating valve on suction side should not be connected directly to pump
suction flange.