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OPERATION AND MAINTENANCE
JMI
FOR
SUBMERSIBLE PROPELLER
J.M.I CO., LTD
PUMPS
TABLE OF CONTENTS
1. PRODUCT DESCRIPTION
2. PROTECTION DEVICES
- Thermal protector (Stator Winding Temperature Sensor)
- Seal Sensor (Leakage Detector)
- Bearing Temperature Sensor
- Moisture Sensor (optional)
3. INSTALLATION
4. BEFORE STARTING
5. ELECTRICAL WORKS
6. OPERATION
7. INSPECTION
8. TROUBLE SHOOTING
9. DESIGN OF PROPELLER PUMP STATION
1. PRODUCTION DESCRIPTION
Design
Watertight cable entrance with anti-wicking
block prevents incursion of water into the
motor even if the power cable is cut or
damaged
Highly efficient, continuous duty, air
filled motor assures low operating cost
and maximum life expectancy.
Double inside mechanical seal
with silicon carbide faces guarantees
long-lasting operation without leakage.
Simple and compact mechanism
prevents twisting of power cables
and pump itself
Highly reliable thermal protector
prevents motor failure caused by
heavy overloads, stalling etc.
Double shielded, permanently
lubricated, high temperature ball bearing rated
for 100,000 hours provide for
extended operational life.
Highly sensitive float type sensor
gives warning of impending seal
failure in advance.
Highly-efficiency and
high-capacity impeller offers
tremendous advantages
Main parts
A. Impeller
The pump is equipped with a propeller of Aluminum
Bronze or Stainless Steel (optional).
B. Shaft
The shaft and rotor are integrated as one part.
The shaft is completely sealed and will not come into
contact with the pumped liquid.
Material: Stainless Steel
C. Shaft Seal
The pump has double mechanical seals, which provides
the necessary isolation between the electric motor and
the pumped liquid.
Material:
Upper Seal: Silicon carbide – Silicon carbide
Lower Seal: Silicon carbide – Silicon carbide
D. Bearings
The pump bearings are designed for at least 50,000 hours
of operation. The lower bearing consists of ball bearings.
The upper bearing consists of a roller bearing.
Features
The features of JPP submersible propeller pumps are:
- Compact design provides for easy handling and installation
- High capacity with low head design is versatile in application
- Simple mechanism provides for easy maintenance special piping or housing is required
- Propeller individually designed for duty point.
Applications
JPP submersible propeller pumps are designed especially for:
- Flood and storm water control
- Drainage/irrigation with large volumes
- Raw water intake
- Large scale municipal sewage treatment plant
- Circulation of large quantity of water in water theme parks and the like.
Specification
Standard
Options
Discharge Size
400 ~ 1,800 mm
Up to 2,000mm
Column Diameter
600 ~ 2,000 mm
Upon request
22 ~ 750 KW
Up to 1,000 KW
Power Range
Water temperature
0 ~ 40℃
Impeller type
Propeller
Performance Range
- Capacity
- Head
20 ~ 480㎥/min
Upon request
Up to 9 m
Materials of Construction
- Casing & Wearing ring
Cast Iron
- Wearing ring
Stainless steel
- Propeller Vane
Stainless steel
- Shaft
Stainless steel
- Motor frame
Cast Iron
Submersible Electric Motor
- Type
- Insulation
- Power cable length
Air filled,
Squirrel cage induction motor
Class F
8m
Aluminum bronze
Part list
Material
No
ITEM
MATERIAL
1
5
6
6-1
10
11
11-1
13
15
25
26
29
30
44
47
50
52
53
54
55
56
59
60
61
63
64
66
68
82
86
90
103
115
148
156
173
Power Cable
Backup Ring
Stuffing Box
Hex. Bolt
Propeller Vane
Propeller Cap
Wrench Bolt
Propeller Hub
Head Cover
Mechanical seal
Oil Seal
Seal Chamber
Suction Casing
Vane Fixed Plate
Discharge Casing
Motor Bracket
Upper Bearing
Thermal Protector
Motor Shaft
Rotor
Stator
Thrust Bearing
Bearing Housing
Bearing Cover
Upper Bearing Cover
Motor Frame
Sunk Key
Lifting Ring
Roller Bearing Cover
Radial Bearing
Seal Leakage Sensor
Cable Bend
Terminal Board
Bearing Temp. Sensor
Shaft clamp Washer
Wearing Ring
OIL
PAINT
PREMIER
304 SS
Cast Iron
304 SS
SSC 13
Cast Iron
304 SS
Cast Iron
Cast Iron
SiC / SiC
NBR
Cast Iron
Cast Iron
304 SS
Cast Iron
Cast Iron
410 SS
Cast Iron
Cast Iron
Cast Iron
Cast Iron
410 SS
Steel
Cast Iron
Cast Iron
Cast Iron
304 SS
SSC 13
ISO VG #32
Epoxy Paint Black
Epoxy Paint Brown-Red
ASTM
ASTM A276, 304
ASTM A48, Cl. 30
ASTM A276, 304
ASTM A743, CF-8
ASTM A48, Cl. 30
ASTM A276, 304
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A276, 304
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A276, 410
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A276, 410
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A48, Cl. 30
ASTM A276, 304
ASTM A743, CF-8
-
STANDARD
BS
BS970-70, 304S15
BS1425-77, 180
BS970-70, 304S15
BS1425-77, 180
BS970-70, 304S15
BS1425-77, 180
BS1425-77, 180
BS1425-77, 180
BS1425-77, 180
BS970-70, 304S15
BS1425-77, 180
BS1425-77, 180
BS970-70, 410S21
BS1425-77, 180
BS1425-77, 180
BS1425-77, 180
BS1425-77, 180
BS970-70, 410S21
BS1425-77, 180
BS1425-77, 180
BS1425-77, 180
BS970-70, 304S15
-
JIS
SUS304
FC 200
SUS304
SCS13
FC 200
SUS304
FC 200
FC 200
FC 200
FC 200
SUS304
FC 200
FC 200
SUS410
FC 200
FC 200
FC 200
FC 200
SUS410
FC 200
FC 200
FC 200
SUS304
SCS13
-
Exploded diagram
No
Description
No.
Description
Overhaul sequence
1) Lifting ring
2) Empty Oil
3) Head cover
4) Terminal board
5) Discharge casing
6) Cap
7) Vane washer
8) Vane
9) Key
10) Seal chamber
11) Suction casing
12) Mechanical seal
13) Bearing housing
14) Motor bracket
15) Upper bearing cover
16) Lower seal chamber
17) Lower bearing cover
18) Lower stop ring
19) Bearing
2. PROTECTION DEVICES
Sensors for JPP
Sensor
Built - in
Motor rating
Type
Standard
22 KW above
Bi-metal
Optional
90 KW above
PT-100 Ohm
Standard
22KW above
Float type
Optional
22KW ~75KW
Thermal protector (TP)
Seal Leakage Sensor (SS)
Bearing Sensor (BS)
Moisture Sensor (MS)
PT-100 Ohm
Standard
90 KW above
Optional
90 KW above
Electrode
Location of sensors
Thermal protector (Winding temperature sensor)
A temperature sensor is installed in the stator windings of motor
Which continuously monitors temperature of the motor.
The sensor has two lead wires and is identified by the letters TP.
The thermal sensor is a Bimetal (General) or PT-100 Ohms type
(Optional).
The function operates if the motor stator winding temperature
exceeds a programmable preset temperature.
This happens when the temperature reach to over 100 °C and
The indication lamp (TP) of Monitoring Unit System (MUS) turns on.
The use of a MW tester to test this alarm is prohibited due to
the low resistance of the sensor circuits.
Seal leakage sensor(Seal sensor)
A seal leakage sensor is installed on the bearing housing.
This is an Float type sensor to determine if water penetrates into the oil chamber
due to the abrasion or mechanical seal failure.
The sensor has two lead wires and is identified by the letter SS.
The function operates if the mechanical seal fails allowing water to penetrate the
oil chamber. The indication lamp (SS) of Monitoring Unit System (MUS)
turns on. And the mechanical seal must be replaced and the oil chamber refilled
with fresh oil to the correct level
The use of a MW tester to test this alarm is prohibited due to
the low resistance of the sensor circuits.
Bearing temperature sensor
This sensor is installed in the lower bearing housing and monitors the
bearing temperature. The sensor has two lead wires and identified by
the letter BS. The bearing temperature sensor is a PT-100 Ohms type
sensor.
The function operates if the temperature of the bearing exceeds a programmable preset
temperature.
When this happens, The indication lamp (SS) of Monitoring Unit System (MUS) turns off.
If this function is activated, the bearings should be replaced and the motor
inspected and serviced. The real time bearing temperature can be read
from the digital meter on the front of MUS.
The factory preset temperature for the bearing temperature alarm is
110°C. If necessary, the value can be changed by authorized engineer.
The use of a MW tester to test this alarm is prohibited due to
the low resistance of sensor circuits.
Moisture sensor (Optional)
An optional moisture sensor may be installed in the electrical junction
box to guard against moisture penetration which may cause a short circuit
of cable by moisture. The sensor, if fitted, is connected by two lead
wires and is identified by letter MS. The moisture sensor is electrode
type sensor.
The function operates when moisture is detected in the junction
Box. When this happens, The indication lamp (MS) of Monitoring Unit System
(MUS) turns on.
If this happens, the integrity of the cable entry must be restored
and the insulation resistance of the motor checked. If less than 1.5 kW,
the motor must be dried and preferable serviced before running again.
The use of a MW tester to test this alarm is prohibited due to
the low resistance of the sensor circuits.
Dimension & diagram of MUS
To operate MUS in control panel, AC220V and
relay to get output through it should be prepared.
It also needs a space to be installed in the control
panel.
INPUT(PUMP)
AC(220V)
1 2
T/P
3
S/S
4 5 6
OUTPUT(RALAY)
M/S
B/S
T/P
S/S
M/S
INPUT(PUMP)
COM
Pt 100
(B/S)
7 8 9 10 11 12 13 14 15
Operating manual of MUS
J.M.I Monitoring Unit Systems (hereinafter MUS) is installed in MCC (motor control center) and accordingly MCC manufacturer
should prepare the wiring work for MUS.
So it is strongly recommended to hand over MUS to MCC manufacturer as soon as
MUS manufacturer is selected. MUS is very sophisticated instrument and it has many useful functions. So be careful to use it
properly.
Followings are the operating drills for MUS
1) First of all, please check input line voltage to MUS whether it is within 220V AC,
50 or 60Hz.( both of 50HZ and 60HZ are available)
2) Connect all the sensor wires to proper terminals on MUS
There is a marking in the terminal block for the sensors, so it is easy to identify
the terminals for each sensor
3) Then set the operating mode with following procedure.
(1) Set the bearing temperature (110℃) by using up/down arrow key.
(Generally, Centrifugal pump - 80℃ and Mixed / Axial flow pump - 110℃)
(2) Turn on power switch of MUS.
The display window shows the temperature of bearing.
4) MUS are consist of following,
Mode : M/S + S/S + T/P + B/S
where, M/S = Moisture detecting sensor in junction box (Optional)
S/S = Seal leakage detector
T/P = Thermal protection (Bimetal type sensor)
B/S = Bearing temperature detector
5) When the pump is working at normal,
M/S, S/S and T/P indication lamps are under extinction and Only B/S indication
lamp keeps turning on.
6) In return, M/S, S/S and T/P lamps are turning on and only B/S lamp is turning off
in case of faulty function in the pump.
After acknowledging the error, switch off MUS and remove the faulty source.
In case of the faulty source is removed, Go back to the first procedure.
3. INSTALLATION
Safety precautions
In order to minimize the risk of accidents in connection with the service
and installation work, following safety precautions should be taken.
1. Make sure all lifting equipment is in good condition.
2. Use safety equipment, i.e. helmet, shoes and goggles.
3. Use a licensed electrician and be aware of the risk of electrical accident.
4. Be aware and do not ignore the risk of drowning.
5. A first-aid kit must be handy at all times.
6. Follow all health and safety rules of local ordinances and codes.
Handling equipment
Lifting equipment will facilitate handling of the pump. Only lift and handle
the pump using a winch or wire rope attached to the lifting lug of the
pump. NEVER HANDLE THE PUMP BY THE POWER CABLE.
The capacity of the lifting equipment must be sufficient to handle the load plus an additional 50% safety factor.
Make sure that the lifting equipment is securely anchored to a strong base before using.
WARNING! DO NOT STAND UNDERNEATH THE PUMP WHEN IT IS BEING LIFTED
Cable protection
If the pump is not going to be installed immediately, the open end of the power cable must be protected from
moisture which could otherwise penetrate the motor winding. This should be done as soon as the pump
Delivered..
Installation of submersible propeller pump
The pump is installed in a stationary discharge tube(Column pipe). The pump operates completely submerged
in the discharge flow and does not require any additional protection.
In addition to the pump, the following items are required:
- Column pipe with bottom locating plate(sole plate) in which the pump installed.
- Cable holder for securing the cable and regulating the height of level sensors.
Take particular care installing the propeller pump because the installation method is not similar to that of
other type of submersible pump.
The installation should be carried out by qualified personnel experienced in the installation of this type of pump.
The pump must be installed in compliance with this instruction manual.
1. First measure the depth of the sump (L) and length of the column pipe (L2).
This determines the dimension (L1) which must be above the minimum shown in the table below.
2. The anchor bolts should be pre-installed prior to concrete pour as part of the civil works. If this is not done then mark
out and install the anchor bolts during the installation of the column pipe.
3. To install the column pipe
a. Fit a waterproof membrane between the mounting flange and the concrete support structure.
b. Slowly lower the column pipe into the sump using overhead lifting equipment.
c. Confirm that column pipe is perpendicular and resting securely on the concrete surround.
d. Last, tighten the nuts of anchor bolts ensuring pipe does not move.
4. To install the pump
a. Slowly lower the pump into the column pipe using the overhead lifting equipment.
Carefully guide the pump into position at the bottom of column pipe and rotation stoppers.
The pump is secured by it’s own weight and the rotation stoppers. No additional fixing is required.
b. Secure the cable to the cable holder.
Route the cables through the cable gland and run the cables to the extend to electric junction box.
Secure the cable in the cable gland with the O-ring and the bolts.
c. Pull up the cable coming from stuffing box of pump up to the column pipe cover and keep it tighten up and
tense in order not to be moved from side to side by discharging water.
5. Fit the column pipe cover on the upper part of column pipe using a waterproof gasket & tighten the bolts.
4. BEFORE STARTING
Rotate the propeller by hand in a clockwise direction as viewed from above
(see figure) before installation. When starting the pump the motor torque
will jerk the pump in the opposite direction to the propeller rotation.
Exercise caution as the resulting jerk on large pump can be powerful.
Check that the supply voltage and frequency agree with the specification on
the pump name plate. If not, do not start the pump.
Check that the outer sheathing on the cables is not damaged to ensure
water cannot enter the junction box through the cable. If refitting the cable,
cut off a short piece to ensure the cable entry sealing sleeve does not clamp
around the cable at the same point again. Check that cable entry seal
sealing and washers conform to the outside diameter of cable. When
preparing power cable leads for connection to the pump and control panel,
it is essential that the ground lead must have at least 50 mm slack
remaining after connection. This is to ensure that if the cable is
accidentally pulled out, the ground lead connection will be the last to be
broken.
Your pump is delivered connected for the voltage and frequency on the
name plate and was factory prior to shipment under these conditions.
5. ELECTRICAL WORKS
To minimize the risk of accidents and damage to the pump, all electrical work must be carried out by an
electrician suitably qualified under local licensing laws. All local codes and health and safety rules must be
followed. Before starting work on the pump, the power supply must be locked off or disconnected in such a
way that it cannot be accidentally re-energized during the installation process.
Check of power cable insulation resistance
After completion of the pump installation, check the insulation resistance of the primary and secondary power
cables by measuring between each phase and earth using Mega tester. The result should be over 10MW.
DO NOT test the wires of the protective device. Damage will result.
Now measure the insulation resistance between phases as described overleaf for the appropriate starting method.
Direct on Line
- Connect one of the three phase leads in the power cable to the to lead of the earth link of a Mega tester.
- Measure the insulation resistance between the above phase and each of the other two phase leads.
-If the insulation resistance is less than 1 MW in each case the connection is correct.
Connect the motor than 1 MW there could be a partial open circuit or incorrect internal
connection of the motor. In this case, do not connect the pump. Check the cable and motor
connections, rectify and measure again before connecting.
Star-Delta
- Connect one of the six phase wires in the phase cable to the earth link of a Mega Tester.
- Measure the insulation resistance between the above phase line and
each of the remaining five phase wires.
-Only one measurement should be 0 MW (closed circuit). If more than
one measurement is 0 MW then there is a fault with the internal
connection of the motor or the motor is damaged.
-If the above test is passed connect the leads to the appropriate terminals in the control panel.
When checking pumps wired Star-Delta to D.O.L or Reactor, Follow the table below.
U, Z (1, 6)  R
V, X (2,4)  S
W,Y (3,5)  T
Reactor
-Connect one of the six phase wires in the phase cable to the earth link of a Mega tester and test the wires
in accordance with the same procedure as for star-delta
-If this test is passed then the cables should be connected to the appropriate terminals in the control panel
making sure to combine the wires from the pump in pairs of U & Z, V & X, and W & Y, which should then be
connected to U, V and W in the panel respectively.
Grounding
The earth wire (green color, labeled as “E”) must be connected to ground in the control panel.
Verification that grounding continuity has been established must be confirmed
by checking that the grounding wire is electrically conductive with a bolt on the motor (strip paint on bolt first).
6. OPERATION
Safety precautions
Before staring work on the pump, make sure that the pump and control circuits are isolated from the power
supply and cannot be energized.
Make sure that the pump has been thoroughly cleaned from rubbish and sludge.
In an established operation be aware of the risk of infection and follow the local health and safety regulation.
Direction of propeller rotation
Turn on the power and start the pump. The simplest check for correct rotation is the discharge of water from
the discharge pipe. If not , check the current on the control panel ammeter. If it is low, it confirms that
the pump is under loaded because the pump isn’t pumping water due to the wrong rotational direction.
To change the direction of rotation of the motor interchange the phases as shown in the diagram overleaf.
Direct on line /
Reactor starting
Star-Delta
7. INSPECTION
The Pump should be inspected at least twice a year, more frequently under severe operating conditions.
Normally, the pump should be subjected to a major overhaul in a service shop every third year. This requires
special tools and should be done by an authorized service shop.
When the pump is new or when the seals have been replaced, inspection is recommended after one week of
operation. Regular inspection and preventive maintenance ensure more reliable operation.
Recommendation inspection
Inspection
Visible parts on pump and installation
Pump casing and propeller
Liquid in motor casing
Liquid in the motor casing
Cable Entry
Cables
Starter Equipment
remedy
Replace or fix worn and damaged parts. Make sure that all screws, bolts, and nuts are tight.
Check the condition of carrying handle/lifting eyes, chains and wire rope
Replace worn parts if they impair function. Check clearance between the propeller and the
wear rings. This should be not exceeded 2 mm (5/64 in).
WARNING, if there has been leakage through the seal, the oil chamber may under pressure,
hold a rag over the inspection cover when unscrewing the screw to prevent splatter.
If there is water in the stator casing, the cause may be:
- That an O-ring (15-5, 50-5, 60-5) is damaged. - That the cable entry is leaking.
If there is oil in the motor casing, the cause may be:
- That the inner seal (25) is damaged. - That an O-ring (69-5) is damaged.
Make sure that the cable clamps are tight
If the cable entry leaks:
- Check that the entry is tightened.
- Cut off a piece of the cable, so that the sleeve closes around a new position on the cable.
- Replace the seal sleeve.
- Check that the seal sleeve and the washers conform to the outside diameter of the cables.
Replace the cable if the outer jacket is damaged.
Make sure that the cables do not have any sharp bends and are not pinched.
If faulty, contact an electrician
Rotation direction of pump
Transpose two-phase leads if the impeller does not rotate clockwise
Check the direction of rotation every time the pump is reconnected.
Pipes, valves and other
peripheral equipment
Repair fault and notify supervisor of any faults or defects.
Insulation resistance in
the stator
Use insulation resistance tester set on 100V-DC. Check phase to phase and phase to earth
resistance. Test result should be in accordance with the values set out in section X Check of
power cable insulation resistance according to the starting method of the pump.
Storage
Always lift the pump by its carrying handle of lifting eyes (lifting lugs), never by the motor cable or the hose.
The pump is frost proof as long as it is operating or is immersed in the liquid. If the pump shall be operated for a
short period after being taken up in order to expect all remaining water. Allowing the pump to stand
immersed in the liquid for a short period before it is started can thaw a frozen propeller. Never use an open flame to
thaw the pump. For longer periods of storage, the pump must be protected against moisture and heat.
The propeller should be rotated by hand occasionally (for example every other month) to prevent the seals from
sticking together or if the pump is submersed, operated it for 30 seconds. If the pump is stored for more
than 6 months, this rotation is mandatory.
After a long period of storage, the pump should be inspected before it is put into operation. Pay special attention to
the seals and the cable entry. Clean the pump and spray with rust inhibiting oil, in addition to above,
do not store in direct sun. Store in protected area.
Changing the oil
WARNING, if the primary mechanical seal leaks, the oil casing may under pressure.
Cover the oil plug with a rag to prevent splatter whilst unscrewing.
Completely pump out the used oil making sure that the removal tube goes all the way to the bottom of the casing.
For complete drainage, the pump must be 60°. After refilling, tighten the oil plug.
Replacing the wearing ring
When clearance between the propeller skirt and the pump casing exceeds 2mm (5/64”), the wearing ring must be
replaced. Remove screw and lift the pump off the dell-mouth. Replace wearing ring.
Assemble in opposite order
8. TROUBLESHOOTING
A universal instrument, a test lamp (continuity tester) and wiring diagram are required in order to carry out fault
tracing on the electrical equipment. Fault tracing shall be done with the power supply isolated, except for those
checks that cannot be performed without voltage. Always make sure that there is no one near the pump when it is
connected. Use the following checklist as an aid to fault tracing.
It is assumed that the pump and installation have formerly functioned satisfactorily.
When pump fails to start
Is a fault signal
indicated on the panel ?
Can the pump be
Started manually ?
Is a fault signal
indicated on the starter?
Contact Authorized
Sever ice center
Check the cause:
- If the bearing temperature is high, take the pump to the shop for repair.
-If the stator temperature is high, check that the cooling system is working and
that the propeller rotates easily.
-If there is a fault in thermal protectors, contact an authorized electrician.
Check that the overload protection is reset.
a) Fault in level equipment (start sensor) clean or replace.
b) Fault in control panel.
Check:
- The control voltage is correct. Control fuse is OK.
- That all connections are securely tightened.
- That relay and contactor coils are functioning.
-That the mode selector switch makes contact in each position.
Check:
- That the supply line voltage is correct on all phases.
- That the main power switch is on, fuses intact.
- That the overload protection is reset.
-That there is no break in the motor cable.
When pump starts but stops on motor protection
Is the motor protection set too low ?
(Check with motor data name plate)
Is the propeller difficult to
rotate by hand ?
Adjust
Clean the propeller or clean out the sump
Is the installation receiving full
voltage on all three phase ?
Contact an authorized electrician
Are the phase currents unbalance or
too high ?
Contact an authorized electrician
Is the insulation between the phases
and earth in the stator defective ?
Use an insulation tester set to 1000 V-DC,
check insulation between phases and between phases and earth
(ground) complies with the correct levels for the type of motor starting.
Contact an authorized electrician
Is the density of the pumped liquid
too high? (Max. density 70 lb/ft3)
Fault in motor protection devices
Contact
Authorized service center
Dilute the liquid
Replace defective motor protection devices
When pump does not stop
Is the pump able to empty the sump
to stop level ?
Fault in level sensing
g equipment
Stop level is set too low
Check:
- For leakage in pipe discharge connection
- That the propeller is not clogged
-The valves are open.
Clean the stop sensor
Check the contactor and holding circuit
Replace defective items
Raise the stop level
Contact
Authorized service center
When starts-stops-starts in rapid sequence
Does the pump start due to backflow,
Which fills sump to the start level
again?
Does the contractor’s self-holding
function fail ?
Contact
Authorized service center
Check:
- That distance between the start and stop level is not to small
- The valves (if any)
-Function of non return valve
Check
- Contactor connection
- The voltage in the holding circuit in relation to the rated voltage on the coil.
8. DESING OF SUBMERSIBLE PROPELLER PUMP STATION
The recommendations given in this section are intended as a guide only.
JMI accepts no responsibility for the incorrect design of the civil works whether or not it is based on these
recommendations and dimensions. The provision of a correct & successful design is the responsibility of the
project designer.
Recommended sump dimensions
The design of the pumping station should aim at positioning the pumps and dividing walls, so as to avoid creating
adverse phenomena, such as surface vortices, air ingestion and entrainment, large scale turbulence
and a fully developed air core which result from poor sump design and adversely affect performance.
The following factors need to be considered in the sump design.
- The velocity & distribution of the fluid in the approach channel to the sump should be symmetrical.
- The effects of flow disturbances should be dissipated as far as possible from the pump intakes.
- Stagnation regions should be avoided in design or post design by filling with concrete.
- The maximum velocity of the upstream fluid in the approach channel to the sumps should be 0.3 ~ 0.5 m/sec.
- Vortex shedding should be minimized.
In consideration of the above points recommended dimensions for approach channels are as shown overleaf..
Arrangement of a single pump sump
To properly position a single pump, the pumps approach channel should be in line with the station inlet channel.
The transition from the station inlet to the sump floor beneath the pump should be as possible to
avoid air entrainment and turbulence. The preferred gradient is maximum 15°.
Arrangement of a multiple pump sump
The same design principles for single pump systems are also applicable to multiple pumps. In addition the
uniform flow between each pump must be established by diving walls between adjacent pumps. Each individual
sump should be dimensioned as for a single pump installation.
In order to ensure a uniform flow on all pumps, a sudden expansion of the station inlet must be avoided.
The preferable transition diffuser angle is 20° maximum.