As the name suggest, a flow meter is a device or an instrument used to measure linear, nonlinear, mass or volumetric flow rate of a liquid or a gas. Different types of flow meters are available for different application and depending upon the requirement, a careful selection of flow meter is made. For e.g., a Turbine type flow meter cannot be used for measuring the flow in an unclear liquid (waste water or corrosive liquids). |
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Basic types of digital flow meters commonly applied in the industry:
- Turbine Flow meter
- Electromagnetic Flow meter
- Ultrasonic Flow meter
- Mass Flow meter
- Differential Pressure Flow meter
- Vortex Flow meter
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| Selection Criteria
Before selecting a flow meter for an application, certain queries must be answered:
- Application: Liquid or gas
- Type of Liquid : Corrosive / Non Corrosive
- Viscosity of Liquid :
- Flow rate : Min / Max
- Material of construction of wetted parts :
- Liquid type : Clear / Corrosive etc.
- Operating Temperature :
- Operating Pressure :
- Line Size :
- Indicator : Remote or Local
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| Necessary conditions:
There are however certain necessary conditions for any flow meter to work properly to its expectations:
- The pipeline must be completely filled. If the flow passes through incompletely filled pipe lines then erratic readings may occur.
- The flow should be streamlined at the inlet and outlet of the flow meter failing which turbulence may occur thereby the display reading may fluctuate and may incur loss of accuracy to a noticeable extent.
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| Turbine Flow meter (TFM) |
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Turbine Flow meter
Field Mounted Flow rate Indicator
Totalizer
4-20 mA Output Transmitter
Batcher |
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Turbine Flow Meter or Digital Water Meter is employed for fluid flow measurement in clear liquids & also used in gases in general industrial applications for volumetric flow measurement. Turbine Flow meter's performance is outstanding when accuracy, quality & consistency in operation is concerned.
The flowing media imparts a force on the turbine placed in-line, which thereby spins at an angular velocity which is in direct proportion to the flow rate. This velocity is sensed by the sensor and converted to a digital signal by electronic front end inside the instrument. Later on this digital signal is converted to flow rate to display it on the screen onboard. The on-board flow computer designed by Scharf Automation Engineering team, calculates and displays the flow-rate as well as totalized value of liquid or gas that has passed through the meter via pipeline with an amazing accuracy of 1%. On request, we even provide an accuracy of 0.5% and we always strive to achieve better than that.
Electro-magnetic flow meters suffer from the drawback that the flowing media or liquid must be conductive in nature, whereas such is not the case with Turbine Flow meter which provides excellent performance even in non-conductive liquids like kerosene, petroleum, vegetable oil etc. |
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| Electromagnetic Flow meter (EMF) |
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Electro-magnetic Flowmeter
Field Mounted Flow rate Indicator
Totalizer
4-20 mA Output Transmitter
Batcher |
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Under volumetric flow measurement, Electro-magnetic flow meter are used for fluid flow measurement of any conducting liquid like water or slurry that is flowing in closed pipes. Unlike Turbine flow meters, it is obstruction less and hence no drop in pressure is observed in the process line.
Since there are no moving parts hence maintenance is very less. Many flow meters have to be recalibrated if the property of the liquid changes, like corrosiveness, density, viscosity, acidity and alkalinity. In case of Electro-magnetic Flow meters, the performance of the instrument is not affected by any deviation in these properties. Apart from liquids, even in pastes and slurries in water or treated waste water, it can accurately measure the flow rate. Perfect for use in plants of chemicals, fertilizers, paper, dairy, sugar, food etc. |
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| Technical Specifications: |
| Media |
Liquids (Clear) |
Viscosity |
200 cp max |
| Line Size |
15 NB to 300 NB |
Excitation |
Pulsed DC coil |
| Excitation |
Pulsed DC coil |
Display |
Graphical LCD (128x64) |
| Transmitter Output |
4 to 20 mA DC, Optically Isolated |
Relay Output & Rating |
Potentials Free Contacts & 5 Amp / 230 VAC |
| Linearity |
+/- 0.5% |
Accuracy |
+/- 0.5% F.S. |
| Repeatability |
+/- 1% |
Process Temperature |
150 degC max |
| Process Pressure |
10 kg/cm2 max |
Lining |
Neoprene / Rubber / PTFE (Teflon) |
| Flange |
MS/SS304/SS316 |
Electrode |
SS316/Hastalloy C/Titanium/Monel |
| Power Supply |
24 V DC, External |
Power Consumption |
<10 VA |
| Response Time |
< 100 m Sec |
Isolation |
1.4 KV between Input, Output & Power Supply |
| Temperature Coefficient |
+/- 0.1% per DegC |
Transmitter Enclosure |
Flame-proof, IP-65, IIA, IIB CMRI certified |
| Dimensions |
As per chart on rear |
Process Connections |
ASA B 16.5, Flanged |
| Mounting |
In-Line (Horizontal OR Vertical) |
Operating Conditions |
Temperature 0 to 55 C / Humidity 5 to 95% non condensing |
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| Line Size Selector Chart w.r.t. Flow Range |
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| Model No |
Line Size |
A |
B |
C |
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Net Wt. (Kg.) |
| mm |
mm |
mm |
mm |
Liquid Flow Range (m3/hr) at the following Velocity |
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0.5 m/s |
1 m/s |
2 m/s |
3 m/s |
4 m/s |
5 m/s |
6 m/s |
7 m/s |
8 m/s |
9 m/s |
10 m/s |
| SAEL300/15 |
15 |
152 |
140 |
290 |
0.3 |
0.6 |
1.1 |
1.7 |
2.2 |
2.8 |
3.3 |
3.9 |
4.4 |
5 |
5.5 |
11 |
| SAEL300/20 |
20 |
152 |
140 |
290 |
0.4 |
0.7 |
1.4 |
2.2 |
2.9 |
3.6 |
4.3 |
5.1 |
5.8 |
6.5 |
7.2 |
11 |
| SAEL300/25 |
25 |
202 |
166 |
316 |
0.6 |
1.2 |
2.5 |
3.7 |
5 |
6.2 |
7.5 |
8.7 |
10 |
11.2 |
12.5 |
12 |
| SAEL300/40 |
40 |
202 |
166 |
316 |
1.8 |
3.7 |
7.3 |
11 |
14.7 |
18.3 |
22 |
25.7 |
29.3 |
33 |
36.6 |
15 |
| SAEL300/50 |
50 |
202 |
166 |
316 |
3.3 |
6.5 |
13 |
19.5 |
26.1 |
32.6 |
39.1 |
45.6 |
52.1 |
58.6 |
65.1 |
16 |
| SAEL300/65 |
65 |
332 |
362 |
233 |
5.1 |
10.2 |
20.4 |
30.5 |
40.7 |
50.9 |
61.1 |
71.3 |
81.4 |
91.6 |
101.8 |
22 |
| SAEL300/80 |
80 |
332 |
362 |
233 |
8 |
15.9 |
31.8 |
47.7 |
63.6 |
79.5 |
95.4 |
111.3 |
127.2 |
143.1 |
159 |
28 |
| SAEL300/100 |
100 |
332 |
362 |
233 |
15 |
29 |
59 |
88 |
118 |
147 |
176 |
206 |
235 |
265 |
294 |
35 |
| SAEL300/125 |
125 |
450 |
336 |
486 |
22 |
44 |
88 |
133 |
177 |
221 |
265 |
309 |
353 |
398 |
442 |
44 |
| SAEL300/150 |
150 |
450 |
336 |
486 |
33 |
65 |
131 |
196 |
261 |
327 |
392 |
457 |
523 |
588 |
653 |
64 |
| SAEL300/200 |
200 |
450 |
336 |
486 |
59 |
119 |
238 |
356 |
475 |
594 |
713 |
832 |
951 |
1069 |
1188 |
86 |
| SAEL300/250 |
250 |
450 |
433 |
583 |
92 |
184 |
368 |
552 |
735 |
919 |
1103 |
1287 |
1471 |
1655 |
1839 |
102 |
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