Badger Meter Vortex Meters User Manual
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09-VRX-UM-00408 07/12
FLOW PROFILING
If the purchased fl ow meter is long enough to be inserted to the far side of the pipe, the fl ow through the pipe may be profi led
at various fl ow rates. The goal is to fi nd a point in the pipe that remains a consistent percentage of the average fl ow rate over a
wide range of fl ow. A sample fl ow profi le is shown in Table A2. In this example, the fl ow rate of a 48 inch pipe is measured every
six inches across the diameter of the pipe beginning and ending 3 inches from the near and far sides of the pipe. The distance
in inches from the nearside of the pipe is shown. Measurements are taken at a low, medium and high average fl ow. In Table
A3 the fl ow rate at each measurement point has been converted to a percentage of the average fl ow. It can be seen that point
number three (15 inches from the near side of the pipe) reads a consistent 102 percent of the average fl ow. The meter should
be placed in this position and the output should be divided by 1.02 to obtain the correct reading. Flow profi ling should be done
for all insertion meter installations.
FLOW
FLOW RATE AT MEASUREMENT POINT (F/S)
1
2
3
4
5
6
7
8
AVERAGE (ft/s)
LOW FLOW
1.90
2.00
2.04
2.06
2.06
2.04
2.00
1.90
2.0
MEDIUM FLOW
5.58
5.91
6.12
6.21
6.24
6.18
6.06
5.70
6.0
HIGH FLOW
10.92
11.70
12.24
12.48
12.60
12.48
12.18
11.40
12.0
DISTANCE
3
9
15
21
27
33
39
45
INCHES
TABLE A2 - FLOW PROFILE (RAW DATA)
FLOW
FLOW RATE AT MEASUREMENT POINT (%)
1
2
3
4
5
6
7
8
LOW FLOW
95.0
100.0
102.0
103.0
103.0
102.0
100.0
95.0
MEDIUM FLOW
93.0
98.5
102.0
103.5
104.0
103.0
101.0
95.0
HIGH FLOW
91.0
97.5
102.0
104.0
105.0
104.0
101.5
95.0
TABLE A3 - FLOW PROFILE (NORMALIZED DATA)
REDUCING THE PIPE DIAMETER
To decrease the variation of fl ow profi le, the piping can be narrowed at the fl ow meter as shown in Figure A7. This will smooth
the fl ow and increase the eff ectiveness of fl ow profi ling. Nearly any angle can be used on the down-stream side of the meter to
restore the original pipe diameter. However, if the angle of piping is seven degrees or less, nearly all the pressure drop caused
by the narrow pipe section will be recovered.
FIGURE A7 - MAKING REDUCTIONS OR ENLARGEMENTS
RUN
PROGRAM
RELAY 1
RELAY 2
30°
7°
3d
1d
d
D
Flow