FLOW MEASUREMENT
Product Code
316
Instruction manual
Contents
1
2
3
4
Description
Specifications
Installation requirements
Installation Commissioning
19-09-2008
5
6
7
8
Troubleshooting
Components used
Packing slip
Warranty
Im316
9 Theory
10 Experiments
11 Components’ manuals
Page 1
Apex Innovations
Description
The set up is designed to study
following different type of units
used for flow measurement.
1) Venturimeter
2) Orifice meter
3) Pitot tube
4) Rotameter
5) Water meter
Setup
consists
of
flow
measurement units under study,
supply tank, Submersible pump
for closed loop water circulation,
acrylic measuring tank with
graduated scale and differential
pressure measuring arrangement
mounted
on
stand
alone
structure.
Rotameter
Pitot tube
Measuring
Tank
Orifice
Venturi
Watermeter
V2
V1
Pump
Specifications
Product
Product code
Venturimeter
Orifice meter
Pitot tube
Rotameter
Water meter
Supply tank
Measuring Tank
Pressure difference
Pump
Piping
Overall dimensions
Flow Measurement
316
Size 18.5 mm, Bore 10 mm, Acrylic
Size 18.5 mm, Bore 12 mm, Acrylic
Size 18.5 mm, Acrylic
60-600 LPH
Size ½”BSP, brass, Least count 1 lit
SS304
Capacity 3 lit, Acrylic
Tube with graduated scale
Fractional horse power, type submersible
¾“ BSP, CPVC
550Wx475Dx690H mm
Shipping details
Gross volume 0.31m3, Gross weight 79kg, Net weight 38kg
Installation requirements
Electric supply
Provide 230 +/- 10 VAC, 50 Hz, single
phase electric supply with proper
earthing. (Neutral – Earth voltage less
than 5 VAC)
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• 5A, three pin socket with switch (1
No.)
Water supply
Distilled
water
@10
liters
Page 2
Apex Innovations
Installation Commissioning
INSTALLATION
• Unpack the box(es) received and ensure that all material is received as per
packing slip (provided in instruction manual). In case of short supply or breakage
contact Apex Innovations / your supplier for further actions.
• Remove packing wire inserted in the rotameter.
• Remove loose components inside the supply tank. Fit small loose pipe to the drain
valve provided at the bottom of the measuring tank. Place the supply tank below
the set up.
• Electric supply: Before connecting electric supply ensure that supply voltage is 230
V AC and earth neutral voltage is less than 5 V Ac.
COMMISSIONING
•
•
•
•
•
•
•
•
Remove the supply tank and fill with distilled water. Place the supply tank at its
location. Note that the measuring tank drain pipe is inside the supply tank.
Ensure that the vent valve on the rubber bulb is fully closed.
Fit rotamter outlet pipe
Keep the flow regulating valve (V1) 50% open, keep drain valve (V2) 100% open
and switch on the pump.
Check the working of rotameter by manipulating flow regulating valve (V1)
Set the flow rate to 60 lph. Press rubber bulb 2-3 times to lower down the water
levels in the manometer tubes. Gently tap the manometer tubes to remove air
entrapped.
Loosen the vent valve on the rubber bulb slightly. The water shall rise in
manometer tubes. Set the water level at mid scale of the manometer. Ensure
that total air bubbles are removed by varying the flow rate from minimum to
maximum range. (The average level in the manometer can be raised by slightly
venting out the air from vent valve of the air bulb or it can be lowered by
pumping air by rubber bulb.)
NOTE: For longer shut down, remove water from the supply tank and clean it.
Troubleshooting
Note: For component specific problems refer components’ manual
Components used
Components
Details
Rotameter
Make Eureka, Model PG 7, Range 60-600 lph,
Connection ¾” BSP vertical, screwed, Packing
neoprene
Make Ananad, Model KNS 15, Class A, Type Multijet,
non magnetic, Size 15mm (1/2” BSP) with end
connection
Submersible pump, Model HQB 4500, Head max.
4.5m, Output 4500 lph, Watts 100, Volts 220-240
Water meter
Pump
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Page 3
Apex Innovations
AC, 50Hz
Packing slip
Box
No.1/1
1
2
Size W595xD670xH800 mm; Vol:0.31m3
Set up assembly
Instruction manual CD (Apex)
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Im316
Gross weight: 79 kg
Net weight: 38 kg
1 No
1 No
Page 4
Warranty
This product is warranted for a period of 12 months from the date of supply against
manufacturing defects. You shall inform us in writing any defect in the system
noticed during the warranty period. On receipt of your written notice, Apex at its
option either repairs or replaces the product if proved to be defective as stated
above. You shall not return any part of the system to us before receiving our
confirmation to this effect.
The foregoing warranty shall not apply to defects resulting from:
Buyer/ User shall not have subjected the system to unauthorized alterations/
additions/ modifications.
Unauthorized use of external software/ interfacing.
Unauthorized maintenance by third party not authorized by Apex.
Improper site utilities and/or maintenance.
We do not take any responsibility for accidental injuries caused while working with
the set up.
Apex Innovations Pvt. Ltd.
E9/1, MIDC, Kupwad, Sangli-416436 (Maharashtra) India
Telefax:0233-2644098, 2644398
Email: [email protected] Web: www.apexinnovations-ind.com
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Page 5
Theory
1) Venturimeter
The venturi is particularly adapted to installation in pipelines not having long,
unobstructed runs. The flow of fluid through the venturi tube establishes the
pressure differential, which can then be measured and related to the flow rate.
Because of the gradual reduction in the area of flow there is no vena contracta and
the flow area is a minimum at the throat so that the coefficient of contraction is
unity.
The meter is equally suitable for compressible and incompressible fluids.
Following figure shows general construction details.
Venturimeter
Flow
Upstream
0
0
19 -23
D/2
d
d/2
0
0
7 -15
D
Downstream
d
The flow through the venturimeter and hence through the pipe is given by
Q=
a1 × a 2 2 gH
a12 − a 2 2
Where
Q = Theoretical discharge m3/sec.
a1 = Area of venturimeter at inlet m2.
a2 = Area of venturimeter at throat m2.
g = Acceleration due to gravity m/sec2.
H = Differential pressure head in m of liquid
In actual practice the actual discharge is less than the theoretical discharge.
The coefficient of discharge Cd is defined as ratio of actual discharge to theoretical
discharge.
Coefficient of discharge (Cd) =
Actual disch arg e
Theoretical disch arg e
Thus the equation for actual discharge Qa becomes
Q a = Cd X
Q a = Cd X
a1 × a 2 2 gH
a12 − a 2 2
K H where
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Page 6
K=
a1 × a 2 2 g
a12 − a 2 2
is known as venturimeter constant.
2) Orificemeter
The orifice meter consists of a thin circular metal plate with circular sharp edge hole
in it. The concentric orifice is by far the most widely used. As the fluid passes
through the orifice, it contracts in area. The minimum flow area is called vena
contracta.
Different types of taps are used for orifice mete. The flow of fluid
through the orifice meter establishes the pressure differential across the orifice plate,
which can then be measured and related to the flow rate
Orificemeter
Orificemeter
Flow
d
Upstream
D
D/2
D
Downstream
The Actual discharge through orifice meter is given by
Qa =
Cc × a 2 gH
1 − Cc 2 (d / D )
4
Where
Qa = Theoretical discharge m3/sec.
Cc = Coefficient of contraction
a = Area of orifice in m2.
g = Acceleration due to gravity m/sec2.
H = Differential pressure head in m of liquid
d = Diameter of orifice in m.
D = Diameter of pipe in m.
The above expression can be written as
Qa =Cd X a ×
where Cd =
2 gH
Cc
1 − Cc 2 (d / D )
4
is known as coefficient of discharge
3) Pitot tube
The Pitot tube is primarily a device for measuring fluid velocity. It is combination of a
total head tube and a static tube. It consists simply of a tube supported in the pipe
with the impact opening arranged to point directly towards the incoming fluid. This is
called the impact opening and is used to measure the stagnation pressure. The static
pressure is measured through the ordinary pressure tap.
The difference between impact pressure and static pressure represents velocity
head.
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Pressure difference (H) = Velocity head = v2/2g
Hence velocity through pipe =
Pitot tube
2× g × H
Piezometric
Static
pressure
tube
Impact
Pitot tube
pressure
Flow
D
Impact opening
4) Rotameter
Rotameter is a variable area meter. In the variable area meter, the drop in pressure
is constant and the flow rate is a function of the area of the constriction.
A rotameter consists of a tapered tube with the smallest diameter at the bottom. The
tube contains a freely moving float, which rests on a stop at the base of the tube.
When the fluid is flowing the float rises until its weight is balanced by the up thrust
of the fluid, its position then indicating the rate of flow. The area for flow is the
annulus formed between the float and the wall of the tube.
(The fig. below shows schematic details of rotameter tube and float. Use top edge of
the float to note rotameter reading)
Rotameter
Outlet float stop: To prevent float from
leaving flowmeter tube at high flow
Maximum flow rate due to maxiimum annular
area is obtained at top end of tube
Fl u i d p a s s e s th ro u g h th i s a n n u l a r a re a
Edge
Metering float
Tapered glass metering tube
Minimum flow rate due to minimum annular
area is obtained at bottom end of tube
Packing
Metering float
Flow
Inlet float stop: To prevent float from
leaving flowmeter tube at no flow
5) Water meter
Water meters are used for measuring cumulative water flow. The meter contains
a rotating vanes housed in side a cylindrical body. The flow of water through the
meter results in the positive displacement of vanes. The water enters in to slotted
casing forcing the vanes to rotate about vertical axis. The cumulative flow of water is
obtained by gearing rotational motion of the vanes to a counter.
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Page 8
(The fig. below shows internal construction of water meter. Black digits show
cumulative flow in Kiloliters. Next two digits in red show reading in further decimals
of kiloliters. The small round dial in red shows reading in liter. The wiper blades can
be used for cleaning the cover window from inside.)
Watermeter
00000 00
Wiper
,x0.01
9 01
2 3
7 8
Kiloliters
4 56
x1liter
Top cover
Cover window
Rubber packing
Gear attachement
Support packing
Body
Water outlet slot
Vanes
Flow
Flow in
out
Water entry slot
Slotted casing
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Page 9
Experiments
1. TO CALCULATE COEFFICIENT OF DISCHARGE OF VENTURI
METER
Procedure
• Start the set up as explained in commissioning.
• Adjust rotameter flow rates in steps of 50 LPH from 60 to 600 LPH and wait for few
minutes till the steady state is reached.
• Note the pressure difference across the venturi meter.
• Close the outlet valve at the measuring tank.
• Measure the time required for collecting 1.5 lit of water in measuring tank by
stopwatch.
• Drain the measuring tank by opening the drain valve (immediately).
Observations
Sr.
No.
1
2
3
4
5
Rotameter Time reqd Actual
reading
for
1.5 discharge
(Lph)
liters (sec) (Lph)
t
60
100
150
200
Theoretical Coeff. of Reynolds
Pressure
diff. across discharge discharg Number
e
Venturi (m) (Lph)
H
Calculations
Venturimeter specification:
Inlet pipe diameter (D)
Throat diameter (d)
Constants:
Acceleration due to gravity (g)
Quantity of water measured (Q)
Density of water (ρ)
Viscosity of water (µ)
= 0.0185 meter
= 0.010 meter
=
=
=
=
9.81 m/sec
1.5 X 10 -3 m3.
998 kg/m3
1.00X10-3 kg/m.s
Equations used:
1. Inlet area of the venturi meter (a1) =
π
× D 2 ….m2
4
π
2. Throat area of the venturi meter (a2) = 4 × d …m2
3. Venturimeter constant (K) =
2
a1 × a 2 2 g
a12 − a 2 2
Q
…m3/sec
t
5. Theoretical discharge (QT) = K H …m3/sec
4. Actual discharge (Qa) =
6. Coefficient of discharge (Cd) = Qa / QT
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7. Velocity in pipe (V) = Qa /a1
8. Reynolds No. = ρ.V.D/µ
Graphs
1. Coefficient of discharge versus Reynolds number
2. Actual discharge versus theoretical discharge
Sample calculations & results
Refer worksheet “Venturimeter” in MS Excel file “316.xls” for calculation and graph
plotting.
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Page 11
2. TO CALCULATE COEFFICIENT OF DISCHARGE OF ORIFICE
METER
Procedure
• Start the set up as explained in commissioning.
• Adjust rotameter flow rates in steps of 50 LPH from 60 to 600 LPH and wait for few
minutes till the steady state is reached.
• Note the pressure difference across the orifice meter.
• Close the outlet valve at the measuring tank.
• Measure the time required for collecting 1.5 lit of water in measuring tank by
stopwatch.
• Drain the measuring tank by opening the drain valve (immediately).
Observations
Sr.
No.
1
2
3
4
Theoretical Coeff. of Reynolds
Rotameter Time reqd Actual
Pressure
reading
for
1.5 discharge diff across discharge discharg Number
e
(Lph)
liter (sec)t (Lph)
orifice (m) (Lph)
H
60
100
150
200
Calculations
Orificemeter specification:
Inlet pipe diameter (D)
= 0.0185 meter
Orifice diameter (d)
= 0.0122 meter
Constants:
Acceleration due to gravity (g)
= 9.81 m/sec
Quantity of water measured (Q) = 1.5 X 10 -3 m3.
Density of water (ρ)
= 998 kg/m3
Viscosity of water (µ)
= 1.00X10-3 kg/m.s
Equations used
π
1. Inlet area of the orificemeter (A) = 4 × D …m2
π
2
2. Orifice area of the meter (a) = 4 × d …m2
2
Q
…m3/sec
t
4. Theoretical discharge (QT) = a × 2 g × H …m3/sec
3. Actual discharge (Qa)=
5. Coefficient of discharge (Cd) = Qa / QT
6. Velocity in pipe (V) = Qa /A
7. Reynolds No. = ρ.V.D/µ
Graphs
1. Coefficient of discharge versus Reynolds number
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2. Actual discharge versus theoretical discharge
Sample calculations & results
Refer worksheet “Orificemeter” in MS Excel file “316.xls” for calculation and graph
plotting.
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Page 13
3. TO CALCULATE COEFFICIENT OF DISCHARGE OF PITOT TUBE
Procedure
• Start the set up as explained in commissioning.
• Adjust rotameter flow rates in steps of 50 LPH from 60 to 600 LPH and wait for few
minutes till the steady state is reached.
• Note the pressure difference between impact pressure and static pressure.
• Close the outlet valve at the measuring tank.
• Measure the time required for collecting 1.5 lit of water in measuring tank by
stopwatch.
• Drain the measuring tank by opening the drain valve (immediately).
Observations
Sr.
No.
1
2
3
4
Rotameter Time reqd Actual
Pressure
reading
for
1.5 discharge difference
(Lph)
liters (sec) (Lph)
(m) H
t
60
100
150
200
Theoretical Coeff. of Reynolds
discharge discharg Number
(Lph)
e
Calculations
Pitot tube specification:
Inlet pipe diameter (D)
=
Constants:
Acceleration due to gravity (g)
Quantity of water measured (Q)
Density of water (ρ)
Viscosity of water (µ)
0.0185 meter
=
=
=
=
9.81 m/sec
1.5 X 10 -3 m3.
998 kg/m3
1.00X10-3 kg/m.s
Equations used
π
1. Inlet area of the pitot tube meter: (A) = 4 × D
2
…m2
Q
…m3/sec
t
3. Theoretical fluid Velocity (V)= 2 × g × H … m/sec
2. Actual discharge (Qa) =
4. Theoretical discharge (QT)= A × V …m3/sec
5. Coefficient of discharge (Cd) = Qa / QT
6. Velocity in pipe (V) = Qa /A
7. Reynolds No. = ρ.V.D/µ
Graphs
1. Coefficient of discharge versus Reynolds number
2. Actual discharge versus theoretical discharge
Sample calculations & results
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Refer worksheet “Pitot tube” in MS Excel file “316.xls” for calculation and graph
plotting.
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Page 15
4. TO CALIBRATE AND FIND ACCURACY OF ROTAMETER
Procedure
• Start the set up as explained in commissioning.
• Adjust rotameter flow rates in steps of 50 LPH from 60 to 600 LPH and wait for few
minutes till the steady state is reached.
• Close the outlet valve at the measuring tank.
• Measure the time required for collecting 1.5 lit of water in measuring tank by
stopwatch.
• Drain the measuring tank by opening the drainn valve (immediately).
Observations
Sr.
No.
1
2
3
4
Rotameter
reading
(Lph)
60
100
150
200
Time reqd
1.5
liters
water (sec)
for
of
Actual
discharge
(Lph)
Error
(Lph)
Accuracy
%
Calculations
1. Actual discharge =
1.5 × 3600
Time reqd for 1.5 liter water
2. Error = Rotameter reading - Actual discharge
3. Accuracy =
Error
× 100
Full flow of Rotameter
Graphs
1 Plot the graph of Actual discharge versus rotameter reading.
2 Plot the graph of Accuracy versus Rotameter reading.
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5. TO FIND ACCURACY OF WATER METER
Procedure
• Ensure clean water in supply tank and switch on the pump.
• Ensure that the outlet valve at the measuring tank is open.
• Adjust rotameter flow rate to say 300 LPH and wait for few minutes till the steady
state is reached.
• Note the reading of water meter and start the stop watch.
• Note the water meter reading after some time interval say 15 minutes.
Observations
Time interval for which the reading is taken: t minutes
Sr. Rotamet *Initial water
No. er
flow meter
rate LPH reading
(F)
(Liters) A
*Final water
meter
reading
(Liters) B
Water
quantity
by water
meter
(Liters)
(B-A)
Water
Error
Accuracy
quantity
(Liters) (%)
by
rotameter
(Liters)
F*t/60
1
2
3
4
*(Please note multiplication factors on the water meter)
Calculations
1. Water quantity by water meter = Final water meter reading - Initial water
meter reading
2. Error = Water quantity by water meter – Water quantity by rotameter
Accuracy =
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Error
× 100
Indicated water quantity
Im316
Page 17
Components’ manuals
Rotameter (PG series)
Rotameter works on the principle of variable area. Float is free to move up & down in
a tapered measuring glass tube. Upward flow causes the float to take up a position in
which the buoyancy forces and the weight are balanced. The vertical position of the
float as indicated by scale is a measurement of the instantaneous flow rate.
Technical specifications
Model
Make
Flow Rate Max.
Packing/Gaskets
Measuring tube
Float
Cover
Accuracy
Range ability
Scale length
Max. Temp.
Connection
PG-1 to 21
Eureka Industrial Equipments Pvt. Ltd.
4000 to 40000 Lph
Neoprene
Borosilicate glass
316SS
Glass
+/-2% full flow
10:1
175-200mm.
2000C
Flanged and Threaded, Vertical
Principle of operation
The rotameter valves must be opened slowly and carefully to
adjust the desired flow rate. A sudden jumping of the float, which
may cause damage to the measuring tube, must be avoided.
Fig.1
Edge
The upper edge of the float as shown in fig. 1 indicates the rate of flow. For
alignment a line marked R.P. is provided on the scale which should coincide with the
red line provided on measuring tube at the bottom.
Maintenance
When the measuring tube and float become dirty it is necessary to remove the tube
and clean it with a soft brush, trichloroethylene or compressed air.
Dismantling of the measuring tube
• Shut off the flow.
• Remove the front and rear covers.
• Unscrew the gland adjusting screws, and push the gland upwards incase of bottom
gland and downwards incase of top gland. Then remove the glass by turning it to
and fro. Care should be taken, not to drop down the glands. Float or float
retainers. The indicating edge of the float should not be damaged.
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Fitting of the measuring tube
Normally the old gland packing is replaced by new ones while fitting back the
measuring tube.
• Put the glands first in their position and then put the packing on the tube.
• Insert the tube in its place.
• Push the glands downwards and upwards respectively and fix them with the gland
adjusting screws.
• Tighten the gland adjusting screws evenly till the gap between the gland and the
bottom plate is approximately 1mm. In case, after putting the loflometer into
operation, still there is leakage, then tighten the gland adjusting screw till the
leakage stops.
• Fix the scale, considering the remark given in the test report.
• Fix the front and rear covers.
Troubleshooting
Problem
Leakage on glands
Showing high/low flow rate than
expected
Showing correct reading initially but
starts showing high reading after
few days
Showing correct reading initially but
starts showing high reading after
some months.
Fluctuation of float
Check
Replace gland packing
Consult manufacturers
Replace float
Incase of gases, check also leakage
Clean the rotameter by suitable solvent or
soft brush
Maintain operating pressure as mentioned
in test report.
Use loflometer to accommodate correct
flow rate.
Maintain
operating
pressure
below
pressure rating of the tube.
Check piping layout.
Frequent breakage of glass tube
Manufacturer’s address
If you need any additional details, spares or service support for this unit you may
directly communicate to the manufacturer / Dealer / Indian Supplier.
Eureka Industrial Equipments Pvt. Ltd.
17/20, Royal Chambers,
Paud Road, Pune – 411 038.
Email: [email protected]
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