Xylem LSB - Manual (Page 80)

Installation, Operation and Maintenance Instruction Model LSB
LSB 100-english page 76 Revision 02
Artikel Nr. 771076129 Ausgabe 01/2010
2.7.7 Electric switches and control device,
Instrumentation and accessories
Electric switches and control devices,
instrumentation and accessories must
correspond with the valid safety requirements
and regulations for explosion protection.
2.8 Use acc. to Regulations
2.8.1 Speed, Pressure, Temperature
Suitable safety measures must be taken at the
plant to ensure that the speed, pressure and
temperature of the pump and the shaft sealing
do not exceed the limit values given in the data
sheet and / or order confirmation. The given
admission pressures (system pressures) must
also be sufficiently high.
Further, pressure shocks, as can occur on too fast
shut down of the facility, must be kept away from the
pump (e.g. by non-return valve at pressure side,
airtanks). Quick temperature changes must be
avoided. They could cause a temperature shock and
lead to damage or impair the function of single
components.
2.8.2 Permitted Nozzle Loads and Torques
Basically the suction and discharge piping must
be designed in such way, that as little forces as
possible are effective to the pump. If that is not
possible, the values shown in chapter 3.5 must
not be exceeded under any circumstances. This
is valid for the operation as well as for the
standstill of the pump and therefore for all
possible pressures and temperatures of the
unit.
2.8.3 NPSH
The pumped liquid must have a min. pressure
NPSH at the impeller inlet, so that cavitation
free work is secured resp. a "break off" of the
pump flow is prevented. This condition is
fulfilled, when NPSH-value of the system
(NPSHA) lies above NPSH-value of the pump
(NPSHR) under all operating conditions.
Attentention must especially be piad to the NPSH-
value on pumping liquids near the vapour pressure. If
the NPSH-value of the pump remains under, this can
lead from damage of the material due to cavitation to
destruction by overheating.
The NPSH-value of the pump (NPSHR) is shown in
the curves of every pump type.
2.8.4 Sealing, Flushing, Cooling
Suitable provisions for the regulation and monitoring of
sealing, flushing or cooling are to be provided.
When handling dangerous liquids or if temperatures
are high, care should be taken to ensure that the
pump ceases operating if the sealing, flushing or
cooling system fails.
Sealing, flushing and cooling systems must always be
operational before the pump is started up. They
should not be taken out of operation until the pump
has stopped, provided that the nature of the operation
allows this at all.
2.8.5 Back Flow
In systems where pumps are operating in closed
circuits under pressure (gas cushions, steam
pressure), the pressure of the gas cushion must not
be reduced via the pump, since the back flow speed
may be much higher than the operating speed, which
would destroy the unit.
3. Description
3.1 Design
LSB-pumps are single-stage volute casing pumps in
block design. Hydraulic design and dimensions comply
with ISO 2858/ EN 22858, the technical design
complies with ISO 5199/EN 25199.
The motors comply with DIN 42677-IM B5. Motor and
pump shaft are coupled rigidly.
The permitted application conditions and design
details of the delivered pump are shown in the
attached data sheet and / or the order confirmation
(see Design Coding System in chapter 3.2).
Installation position: LSB-pump are intended for use
with horizontal shaft, discharge up. Installation
positions deviating therefrom must be approved by the
manufacturer.
3.1.1 Design Coding System
Due to the coding on data sheet and / or order
confirmation all information regarding the delivered
pump can be found in this Installation, Operation and
Maintenance Instruction, e.g.:
LSB 100 - 65 - 250 S1 V L 2 - 132
(0) (1) (2) (3) (4) (5) (6) (7) (8)
Position (0) - Name of Model
LSB - ISO block pump
Position (1) - Suction Nozzle in mm
Position (2) - Discharge Nozzle in mm
Position (3) - Nominal diameter of impeller in mm
Position (4) - Shaft sealing
S1 - Single-mech. seal acc. DIN 24960 l1k /
EN 12756 form U
S4 - Single-mech. seal acc. DIN 24960 l1k /
EN 12756 form U
with Quench (throttle bush)
Position (5) - Material Impeller
N = Cast Iron (0.6025)
L = Ductile Iron (0.7043)
V = Carbon Steel (1.4408)
W = Duplex (1.4517)
Position (6) - Material pump casing (same coding as
impeller, cast iron not available)