Attended for Industrial Course ME 370 offered in Level 4 Term 1 . The Training was for approximately 3 weeks

1. Milnars Pumps Ltd.
89-90 TONGI INDUSTRIAL AREA, GAZIPUR
ME370 INDUSTRIAL TRAINING
REPORT SUBMITTED BY
1410156 SHAFAT SHARAR
1410141 MD. SAMIM UL ISLAM

2. Overview
Milnars Pumps Limited is primarily a pump manufacturing company which also produces a number of
other machine parts. Being one of the rare companies with its own pump testing setup, Milnars Pumps
provides pump testing services as well. Facilities and equipments in the factory are adequate. The
industry primarily focuses on industrial heavy duty pumps, although sometimes they manufacture
household pumps also. This report will discuss on the various departments for pump manufacturing, the
processes each parts of the pump goes through up to export, the production and facilities, the efficiency of
the workers and operators, the role played by the management, any possible ways of improvement, and an
overall picture of the current state of the industry.
History
Milnars Pumps started its journey as KSB Aktiengesellschaft in 1962 in the then East Pakistan. The
German company renamed itself to KSB Pumps Company Bangladesh Ltd after liberation in 1972. After
that the company slowly stopped their business and their license was bought by Aftab Group after some
time and renamed the company to Milnars Pumps Ltd in 1980.
Location
Milnars Pumps Ltd factory is situated at Tongi industrial area. The establishment, similar to many other
industries in the area, is close to Turag river. Local waste management system makes it easy for
processing and transporting factory waste. The nearby market area makes sure the small supplies are
always at hand.
As the factory deals mostly with industrial pumps, transportation of products to other local industries is
very easy and economical.
Being not very far from Dhaka outskirts, it is rather accessible for the people in the capital.
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3. Pump Production
Pumps are obviously the company’s main product. The types of pumps Milnars produces are detailed as
follows:
i. Centrifugal Pumps: These pumps come with a single impeller to accelerate and pressurize the fluid
and a volute casing that increases pressure further, helping the fluid to gain greater delivery pressure.
The factory produces mostly centrifugal pumps. The motors to be paired are imported however. The
models produced are named proprietarily. E.g. : 40-20 AR (smallest, 2” delivery side diameter),
150-26 (largest, 8” delivery side diameter).
ii. Submersible Pumps: These pumps have no suction head and are staged. Most submersibles
produced are 3 phase induction motor coupled. Motors are imported. Some models are : 150QJ
(smallest, 3” diameter), 300QJ (largest, 6” diameter).
iii. Deep Well Turbine Pumps: Also known as DWT pumps, these are similar to submersible pumps
except for that the motor lies on the ground level, coupled by a vertical shaft. These pumps excel in
efficiency from the submersible pumps and operate at a deeper level. However, the amount of noise
generated make it less suitable for urban or suburb areas. Some models are : B6B (smallest), B12B
(largest).
iv. Multistage Centrifugal Pumps: Similar to centrifugal pumps except for that these have multiple
stages i.e. multiple impellers to build a huge pressure on the fluid. Each impeller builds up pressure
atop the previous and so these pumps are suitable for heavy fluid moving industry applications.
Milnars Pumps produces only two models of this pump, MOVI32 and MOVI40.
FIG : CENTRIFUGAL PUMP FIG : SUBMERSIBLE PUMP
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4. Production Line
The various departments in the industry are which the pump parts go through during production. The
major 4 departments are:
i. Foundry Shop
ii. Machine Shop
iii. Assembly Section
iv. Test Bench
Each department is separate from one another in terms of equipments and function.
Foundry Shop
The foundry shop works with the primary part building by casting metal into molds. The method followed
here is conventional with apt equipments available for metal melting and casting for both mass and base
production. The operations in the foundry are by order of part manufacture are as followed:
i. Pattern Making: Patterns used are made of wood. Patterns are what give shape to the molds.
Patterns are of two types : Regular Patterns and Core Patterns. Regular patterns shape a solid part.
Core patterns sit within the Regular pattern to create a hollow space within a part. E.g. the volute
casing has a hollow part where water flows through. So that uses a core pattern alongside the regular
external pattern.
ii. Sand Preparation: Sand is prepared before mold can be made. Sands contain additives in order to
enhance their property. Two types of sand is prepared for different purposes. White sand or regular
sand is SiO2 with some additives for nominal bonding. This sand is cheap and not high heat
sustainable. The mold shape may break at high temperature. The costlier Red sand has more additives
added so bonding is very good and sustained at very high temperatures. This mold sustains shape very
FIG : DEEP WELL TURBINE PUMP FIG : MULTISTAGE CENTRIFUGAL PUMP
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5. well at high temperatures. This sand is used when intricate shape is to be achieved. White sand is used
for rough surfaces.
iii. Mold Preparation: Sand is used accordingly to the required intricacy of the casting. For simple
shape where the exact shape retaining isn’t required, white sand is used as it is cheap. For parts
requiring retainment of shape, red sand is used. Most parts use mixture of both as they have uneven
construction. Mold is shaped either by using molding beds or frames. Conventional method is
followed when making molds.
iv. Metal Melting: The factory has 2 induction furnaces and 1 Cupola furnace. Induction furnaces have
capacities, 200 and 300kg. These are used for mostly base production. The furnace controller used
regulates 425V and 125A current supplied. A transformer is used to regulate the voltage as main line
sometimes fluctuates around 350-360V even. The electric controller is started beforehand to start up
the furnace and it slowly reaches the required voltage and amperage. The Cupola furnace is used
mainly for mass production with a capacity of 5 Tons. Fuel used for this one is mainly coal. Metals
melted are by majority of use:
i. Manganese Steel (Fe.Mn Scrap)
ii. Cast Iron
iii. Mild Steel (Steel rods)
iv. Stainless Steel
v. Aluminum
vi. Bronze
v. Casting: A hydraulic mechanism is used to lift and slant the furnace and load the molten metal charge
into a bucket. The bucket walls are coated with red sand in order to withstand the heat. A crane is
used to lift and unload the charge through the runner.
vi. Cleaning: After the molten metal cools down my natural air flow, the rough extrusions from the
runner and the riser are cut off and the surfaces are cleaned using a steel brush so that little to no sand
remains in the part.
vii. Quenching: For parts with intricate shape, quenching isn’t done. Parts with more or less rough
shapes are quenched with water. The stone crushing jaws that are produced are quenched after further
heating and hardening of the material in a large oven.
After cleaning, the parts are sent to the machine shop for machining and finishing.
The Foundry section of the industry is quite competent and has regular production going on. When pump
parts aren’t being produced, stone crusher jaws are produced. This is very economical for the company as
it’s using the available resources and making profit regularly and continuously. Quite impressive.
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6. FIG : DIFFERENT TYPES OF WOOD PATTERNS
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7. FIG : MOLD PREPARATION FIG : MOLD BED
FIG : IRON MANGANESE SCRAP FIG : STEEL SCRAP
FIG : CLEANING THE SAND FIG : METAL MELTING AND CASTING
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8. Machine Shop
The machine shop is apt with equipments and supply. The machines available at large are:
• Engine Lathes
• Vertical Lathes
• Turret Lathes
• Drilling Machines
• Grinding Wheels
• Milling Machines
The machines are used to do various operations on the rugged parts. Finishing operation is common on all
parts. The operations done on each part are numbered according to the total number of operations for that
part. E.g. the volute casing goes through 5 operations in total. The operations are named, first operation,
second operation and so on. In brief detail these operations are:
i. 1st Operation: Turning is done outside the casing where the impeller will mesh
ii. 2nd Operation: Facing is done in the inner side for the impeller to sit
iii. 3rd Operation: Turning is done on the delivery side to get required diameter
iv. 4th Operation: Drilling is done on the flanges for bolting
v. 5th Operation: Finishing is done by grinding the remaining surfaces with a hand grinding tool
Most notable in the machine shop are the huge vertical lathes. These lathes are fitted with 5 tool turrets.
The turret axis is normal to the vertical motion of the lathe.
The shop is equipped with a good number of engine lathes which are operated most frequently for turning
and facing operations. The small parts are machined here. The lathes with longer bed sizes are used to
machine shafts and pipes. A hydraulic guiding equipments is fitted to the lathe for sizing the shafts as they
have varying diameters along the length.
For every small parts after machining, two separate go-gauge and no go-gauge is used to check the
accuracy of the dimensions. These gauges are of different shapes and sizes according to the part.
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9.
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FIG : VERTICAL LATHES WITH TURRET
FIG : DRILLING MACHINE FIG : HAND GRINDING FIG : LATHE TURNING OPERATION

10. Assembly Section
The assembly section is where all the parts come in machined and ready to put together. The steps
commonly followed for a centrifugal pump assembly is approximately as follows:
i. The volute casing is checked for leak by sealing up the suction and delivery by covers and filling it up
with water. A pressure testing setup is available for this purpose. If the water leaks, then the casing is
marked unusable and sent off to dismantle.
ii. A bearing heater is used to heat up the bearings up to almost 140ºC. This increases the internal
diameter of the bearing so that it easily slips into the shaft. Two bearings are fitted to each shaft to
stay in the bearing housing. Grease is applied to the bearing balls.
iii. The shaft bearing assembly is then rammed into the bearing housing. Lubricant is applied to the shaft
after the assembly is placed in properly.
iv. The volute casing is then bolted on the opposite side of the suction side to the bearing housing. The
other side of the housing is sealed off with a cover.
v. Impeller is inserted through the suction hole and fitted to the shaft using a standoff and an impeller
nut. The assembly section typically has 3 major sizes of impeller nuts for various pump sizes.
vi. Suction side cover is fitted and bolted. There are no leaks at this point as leak testing was done
beforehand.
vii. A coupling disc is fitted to the opposite side of the shaft where a T-slot is located. The disc is meshed
and then a bolt is screwed so the disc doesn’t fall off.
viii.The motor and the pump shaft axes are aligned and meshed via the coupling disc. This alignment is
done by the help of a crane.
ix. During the whole assembly process, lubricant is used abundantly whenever needed at every moving
contacts. Gaskets are used between flanges or any meshing where leak prevention was required.
The assembly section had good number of equipments. However, the whole process is manual and very
time consuming. During mass production the assembly section lags very much due to the slow process.
Absence of automated machinery hurts the production quite a bit.
After the assembly is done, the pump is good to go for testing. Even without the testing, the pump is a
work ready unit at this point. So the pump leaves the production site and for the test bench.
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11.
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FIG : VARIOUS VIEWS OF THE ASSEMBLY SECTION

12.
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FIG : ASSEMBLY OF A CENTRIFUGAL PUMP
FIG : ASSEMBLY SECTION TOOLS
FIG : ASSEMBLY OF A SUBMERSIBLE PUMP FIG : ASSEMBLY OF A SUBMERSIBLE PUMP

13. Test Bench
Performance testing of the pumps is done at the Test bench. A complete setup is available for testing of
pumps having discharge of up to 3 cusec. The flow is separated into an upper and a lower pipe setup. The
lower having a maximum flow capacity of 2 cusec and the upper of 1 cusec for a total of 3. The upper
piping is mainly for overflow, but heavy duty pumps are tested using that part anyway.
There are various equipments available which are used to calculate the Head and the Discharge of a given
pump. These values are used to further calculate efficiency and other related conditions. The discharge is
varied using a flow control valve and the according head is measured from other calculations.
A digital wattmeter is available which gives the readings of supplied current and voltage to the operating
motor. As the power line is a 3 phase line, details of all 3 phases appear on the wattmeter for easy
obtaining of data.
Bourdon pressure gauges are used to measure pressure on the delivery and the suction side (if available).
The velocity of flow can then be figured out.
The area of flow is a V-notch of known geometry. The height (372mm) of which can be used to obtain
area of flow and in turn these data are used to easily measure the flow rate.
The steps followed in the testing procedure for centrifugal pumps are as follows:
i. The pump is mounted on the base frame aligned with a suitable motor
ii. Suction and delivery pipes are fitted as per requirement to ensure proper suction from the pool the
delivery through the V-notch or orifice plate
iii. Valve is fitted on the delivery line to control the flow and pressure as required
iv. A suction gauge is fitted on the suction pipe near the suction flange of the pump
v. A delivery gauge is of suitable range is fitted on the delivery pipe before pressure control valve
vi. The motor is connected to the starter
vii. The motor is started and the readings at different pressures are taken and recorded in the pump test
data and calculation sheet
viii.Calculation is done to obtain the results
The steps followed in the testing procedure for submersible pumps are as follows:
i. The pump-motor is installed on the pool so the the pump is well below the water level
ii. A suitable delivery pressure gauge is fitted through a rubber pipe to read the pressure to the delivering
water at the taping at the middle of the column/rising pipe
iii. The motor is connected to the starter
iv. The motor is started and the readings at different pressures are taken and recorded in the pump test
data and calculation sheet
v. Calculation is done to obtain the results
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14. A sample of how the calculations are done for a centrifugal pump is shown below:
Some numbers used in this calculation directly are due to adjustment of the setup, e.g. different placement
of the pump, custom equipments. Some values like 2.725 in the WHP comes from the equation P =
Q*γ*H, which simplifies by converting the units to the given equation. γ = 9810, Q in seconds means
dividing the term by 3600. So essentially, 9810/3600 = 2.725.
After the testing is done and the pump is rated, it is officially ready for customer handover. The pump is
dried off and packaged with a suitable motor.
Suction gauge reading = Ps in-Hg = Ps x 0.346 m of water
Delivery gauge reading = Pd kg/cm2 = Pd x 10.01 m of water
V notch height = 372mm
Water surface distance from top point of V notch = V mm
Watt meter reading = Wm kW
Total Available Head, " m
Discharge, m3/hr
Working Horse Power, " hp
Input Horse Power, " hp
Combined Efficiency, " %
H = Ps * 0.346 + Pd * 10.21 + 0.34
Q =
(
372 − V
304.8 )
2.47
* 2.52 * 102
WHP =
H * Q * 2.725
746
IHP =
Wm
0.746
η =
WHP
IHP
* 100
H Q WHP IHP Efficiency
1 51.01 70.95 13.22 24.53 53.89
2 61.22 62.55 13.99 24.80 56.41
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15.
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FIG : VARIOUS VIEWS OF THE TEST BENCH

16. Factory Facilities
Milnars Pumps Ltd is a small sized factory but it has a good number of facilities that an industry should
have and sometimes more even. The facilities are primarily, power supply and gas supply.
Power Supply
Gas Supply
Production Rate
The factory doesn’t do very well in pump production. Most of the time, mass production equipments are
turned off. So production mostly depends on customer demand. During the time of the industry visit, an
average of up to 10 pumps per week was assembled. Up to 5 pumps are tested at the test bench daily.
However, despite the low pump production, not all equipments sit idle. The factory produces stone
crusher jaws for stone crushing machines. This machine part has quite a high demand and as per this item
has a production of almost 20 - 100 units per week.
Other small machine parts are also manufactured in the factory.
Supplier : PDB
Connection Type : Industrial 380V 3P
Annual Consumption : 20000-25000 Units (approx.)
Load Factor : N/A
Internal Power Plant : N/A
Backup Supply : 2 Diesel Generators (100KVA, 250KVA)
Supplier : Titas Gas
Connection Type : Natural Gas
Annual Consumption : Data Unavailable
Internal Power Plant : N/A
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17. Comments
From the industry visit we got an overall picture of the state of the industry during that period. The
factory on basis of equipments and facilities is quite remarkable. Since it was a German company and
most equipments from then are still available, and those are very good quality machines. Also additional
equipments have been added over time.
The test bench is a strong suit to the industry as it is one of the rare industries to have one. Many pump
companies rely on Milnars to get their pumps tested.
The most notable negative side to the factory system is bad top level management. Investment in the
current state is negligible. Whereas modern factories are using automated technologies to speed up and
make more efficient their production processes, Milnars sits way behind the competition. Poor investment
and lack of future proof management hurt the overall production of the factory greatly. As we will see,
this is the problem that spreads and causes most other problems of the industry.
The lowest level management also somewhat lacks in hiring skillful workers. Most workers don’t have
proper knowledge of the machines they operate in the machine shop, and just follow steps. This results in
incompetent workflow and a barricade to new ideas being generated from the workers. Also, the machines
aren’t operated efficiently which results in higher depreciation and maintenance cost to the industry.
The assembly section is the weakest section of the factory. Every assembly is done manually. No
automated tools are used even in case of bolting the screws. This process eventually becomes very time
consuming. Even though enough pump parts come in through the machine shop, the assembly section
chokes the production noticeably.
The casting material quality is kept at an acceptable level. The material is tested manually by a chemist.
But if we look at the competing pump factories, they can offer far better material and production pretty
easily due to modern components.
Seeing all the negatives boil down to poor management, we can get a clear picture of how very important
the management sector is to an industry. A strong management can almost always turn the tables for any
business. Our suggestion will be to analyze the current pump market and make heavy investments on
automated technologies all over the factory.
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