Viking SLAL - Manual (Page 6)

fIGURE 8
10
.0
M
et
er
s
(3
2.
8
Fe
et
)W
at
er
C
ol
um
n
Suction Lift
Or Vacuum
Atmospheric
Pressure
Suction
Head
NPSH
Available
Suction Line
Friction Loss
Vapour
Pressure
NPSH
Available
Suction Line
Friction Loss
Vapour
Pressure
For Suction Lift
Or Vacuum
Conditions.
For Conditions
With Positive
Suction Head.
Atmospheric
Vacuum
fIGURE 7
Pump
series
Theoretical
displacement
Nominal
Connection
size
Max diff.
Pressure
Max
speed
Max
Temp
liter
/rev
Imp. Gal
/100 rev
Us gal
/100 rev mm
in. bar psi
rev
/min
°C °f
SLAS 0.039 0.86 1.03 19 3/4” 15 218 1400 150 300
SLAL 0.059 1.30 1.56 25 1” 10 145 1400 150 300
SLBS 0.081 1.78 2.14 25 1” 15 218 1200 150 300
SLBL 0.122 2.68 3.22 38 1 1/2” 10 145 1200 150 300
SLCS 0.169 3.72 4.46 38 1 1/2” 15 218 1200 150 300
SLCL 0.254 5.59 6.71 50 2” 10 145 1200 150 300
SLDS 0.352 7.74 9.30 38 1 1/2” 15 218 1000 150 300
SLDL 0.528 11.61 13.95 50 2” 10 145 1000 150 300
SLES 0.732 16.10 19.34 50 2” 15 218 800 150 300
SLEL 1.099 24.18 29.03 76 3” 10 145 800 150 300
SLFS 1.524 33.52 40.26 76 3” 15 218 600 150 300
SLFL 2.285 50.26 60.36 101 4” 10 145 600 150 300
SLGS 3.17 69.73 83.74 101 4” 15 218 600 150 300
SLGL 4.754 104.58 125.59 152 6” 10 145 600 150 300
SLHS 6.4 140.78 169.07 152 6” 15 218 600 150 300
SECTION TSM 288 ISSUE A PAGE 6 OF 36
Pressure gauges should be installed adjacent
to the pump suction and discharge connections
such that system pressures can be monitored.
These gauges will provide a clear indication of
changes in operating conditions and where a
relief valve is incorporated in the system, will be
necessary for setting and checking the functioning
of the valve.
It is imperative that the suction condition at the
pump inlet meets the Net Positive Suction Head
required (NPSHr) by the pump. Failure to observe
this could cause cavitation, resulting in noisy
operation, reduction in flow rate and mechanical
damage to the pump and associated equipment.
The Net Positive Suction Head available (NPSHa)
from the system must always exceed the Net
Positive Suction Head required (NPSHr) by the
pump.
Observing the following general guidelines should ensure the
best possible suction condition is created.
• Suction piping is at least the same diameter as the pump
connections.
• The length of suction piping is kept to the absolute
minimum.
• The minimum number of bends, tees and pipework
restrictions are used.
• Calculations to determine system NPSHa are carried out for
the worst condition see below.
Should advice on pump or system NPSH characteristics be
required contact the factory or their authorized distributor.
3.4 sYsTEM dEsIGN aNd
INsTallaTION
When incorporating any pump into a system it is considered
good practice to minimize piping runs and the number of pipe
fittings (tees, unions, bends etc.) and restrictions. Particular
care should be taken in designing the suction line, which
should be as short and straight as possible with a minimum of
pipe fittings to minimize restricting product flow to the pump.
The following should be considered at the design stage of any
system.
Be sure ample room is provided around the pump
to allow for:
• Access to the pump and drive for routine
inspection and maintenance, i.e. to remove
pump head and rotors.
• Ventilation of the drive to prevent over
heating.
The exterior of the pump unit may exceed 68°C
(154°F); Appropriate measures must be taken to
warn or protect operators.
The pump must not be used to support piping.
All piping to and from the pump unit must be
independently supported. Failure to observe
this may distort the pump head components
or assembly and cause serious consequential
damage to the pump.
Valves should be provided adjacent to the pump
suction and discharge connections to allow the
pump to be isolated from the system for routine
inspection and maintenance.
Rotary lobe pumps are of the positive displacement
type and therefore an overload protection device
must be provided. This can take the form of:
• An in-line pressure relief system, i.e. external
to the pump.
• Incorporation of a torque-limiting device in the
drive system.
It is recommended that all piping and associated
equipment from the tank to the discharge point
is thoroughly cleaned before installation of the
pump to avoid the possibility of debris entering
the pump and causing damage.
WaRNING
WaRNING
WaRNING
WaRNING
WaRNING
!
!
!