Description; Design; Pump Coding - Xylem LOWARA LR Series Installation, Operation And Maintenance Instructions

Installation, Operating and Maintenance Instruction
2.7.2 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.
2.7.3 NPSH
The pumped liquid must have a min. pressure
NPSH at the impeller inlet; so that cavitations
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.

3. Description

3.1 Design

The pumps of Model LR, LMR, LRZ and LMZ are
single-stage In-line pumps with suction and discharge
nozzle "in-line" and with identical pipe diameter.
Model LR and LMR:
In-line pump with closed radial impeller in block design
with assembled motor.
Model LRZ and LMZ:
In-line pump with closed radial impeller in block design
with assembled motor.
The models LRZ and LMZ are twin pumps with 2
identical driving units, common pump casing and an
integrated flap valve on discharge side.
These pumps are not qualified for dangerous or
inflammable fluids.
operation in areas subject to explosion hazards.
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 Model LR and LMR:
Installed with support foot on base or directly in the
piping in any position, but arrangement with motor
down is not allowed for safety reasons.
Installation position Model LRZ and LMZ:
As Model LR and LMR, but caused by the reversing
flap discharge down is not allowed.
Max. operating pressure: see chapter 3.8.
The appropriate sectional drawing of the supplied
pump as well as the pump weight and the complete
pump unit weight are shown in the appendix.
Not qualified for the
Model LR, LMR, LRZ, LMZ
Attention must especially be paid 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 cavitations to
destruction by overheating.
The NPSH-value of the pump (NPSHR) is shown in
the curves of every pump type.
2.7.4 Back Flow
In systems where pumps are operating in closed
circuits under
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.

3.2 Pump Coding

Due to the coding on the data sheet and / or order
confirmation all information regarding the delivered
pump can be found in this Installation, Operation and
Maintenance Instruction, e.g.:
LMR 65 - 250 U1
(0) (1) (2)
Position (0) - Name of Model
LR / LMR / LRZ / LMZ - block pump design
Position (1) - Suction and discharge nozzle in mm
Position (2) - Nominal diameter of impeller in mm
Position (3) - Design of the shaft sealing
Single mechanical seal acc. DIN 24960 l1k /
EN 12756 Form U, unbalanced
U1 Carbon / Silicon carbide / EPDM
(BQ1EGG)
U2 Carbon / Silicon carbide / Viton (BQ1VGG)
U3 Silicon carbide / Silicon carbide / Viton
(Q1Q1VGG)
Position (4) - Impeller material
N = Cast iron - Model LR, LRZ (0.6020),
Model LMR and LMZ (0.6025)
S = Bronze (2.1050.01), only at model LMR
and LMZ
V = Stainless steel (1.4404), only at model LR,
LRZ
Position (5) - Pump casing material
N = Cast iron - Model LMN (0.6020), Model
LM (0.6025)
Other materials are not available
Position (6) - Motor power (in 1/10 kW)
Position (7) - Number of motor contacts - 2 pole =
2950 rpm resp. 4 pole = 1450 rpm
page 41
pressure (gas cushions,
V N 370 2
(3) (4) (5) (6) (7)
steam