Xylem LMN - Manual (Page 48)

Installation, Operating and Maintenance Instruction Model LM, LMN
LM ger/fr/eng Page 44 Revision 06
Article No 771073101 Issue 08/2013
The size of these insulating pads will vary,
depending on circumstances, and should
therefore be determined by an experienced
specialist.
5.2 Connection of Piping to the Pump
The pump must not be used as fixed point for
the piping. The permitted piping loads must not
be exceeded, refer to chapter 3.7.
5.2.1 Suction and discharge pipe
 The pipes must be of a size and design that liquid
can flow freely into the pump and that the pump
functions without problems. Particular attention is
to be paid to ensuring that suction pipes are
airtight and that the NPSH values are observed.
Under suction lift condition lays the suction pipe in
the horizontal section towards the pump so that it
is slightly inclined upwards so that no air traps
occur. Do not install fittings or elbows right before
the suction nozzle.
 If the suction supply is under vacuum and
entrained gas may be present in the liquid, it is
recommended that a vent line (min. diameter 25
mm) be considered upstream of the pump suction
with return to the suction supply, above the max
liquid level.
 An additional flushed piping - discharge branch-
vent line - makes it easier to de-aerate the pump
before start-up (pic 3).
pic 3
 When laying the pipes, make sure that the pump
is accessible for maintenance, installation and
disassembly.
 Notice "Permitted Forces on Flanges" (chapter
3.7).
 If expansion joints are used in the pipes, they
have to be supported in such a way that the pump
is not loaded unduly high because of the pressure
in the pipes.
 Before connecting up to pump: remove protective
coverings from suction and discharge branches.
 Before starting up, the pipe system, fittings and
equipment must be cleaned to remove weld
spatter, scale etc. Any pollutants are to be
completely removed from pump units that are
directly or indirectly connected to drinking water
systems before being installed and taken into use.
 To protect the shaft sealing (especially mechanical
seals) against foreign impurities, it is
recommended that a sieve, 800 micron, is
installed in the suction / intake pipe when the
motor is being started up.
 If the pipe system is tested with the pump
installed, do not exceed the maximum permitted
casing pressure of the pump and/or shaft sealing
(see data sheet).
 When emptying the pipe after the pressure test,
make sure that the pump is treated properly
(danger of rust and problems when starting up).
5.2.2 Additional connections
The following additional connections are available:
Connection Description Dimension
E Pump drain R3/8"
LA leakage R1/2"
M Pressure gauge R1/4"
V*) Vacuum gauge*) R1/4"
*) ... optional, drilled on request
5.3 Drive
The motor design of the pump is shown in the order
confirmation or on the motor name plate.
Note the Operating Instructions of the motor
manufacturer.
If in the process of repair a new motor is used, the
following has to be noticed:
 The motor must comply with the requirements
stated in sheet 1130.1A608 (order from
manufacturer, on demand).
 Clean motor end and motor flange of new motor
carefully (remove varnish).
5.4 Electric Connection
Electrical connection work may only be carried
out by an authorised professional. The rules
and regulations valid for electrical technology,
especially those concerned with safety
measures, must be observed. The regulations
of the national power supply companies
operating in that area must also be observed.