EFFECTS OF TEMPERATURE
The volume of fuel in your tank will change when the fuel expands or contracts as a result of temperature variations. Temperature of the fuel will vary with the ambient temperature. Its temperature can also change if a fuel pre-heater is used and heated fuel is returned to the tank.
You should make allowances for changes in volume due to temperature, especially when filling the tank. Accordingly, you should allow about 10 percent for expansion. Figure 7 shows the maximum fill levels for Heatec fuel tanks with an allowance of 10 percent for expansion.
Most ambient temperature fluctuations during a 24 hour period will have very little effect on a full tank of fuel. The temperature of the fuel will probably remain close to an average of the ambient temperatures over 24 hours. However, fuel temperatures are apt to change to a greater extent over several weeks or months, when the weather changes from one season to another.
Figure 8 shows how changes in fuel temperature affects its volume. The volumes shown for 60 degrees F correspond to the capacities of standard Heatec tanks. The temperatures should be regarded as average temperatures over a period of 24 hours.
TROUBLESHOOTING TRANSMITTERS
Pockets of air or trash trapped in the pipe where the transmitter is connected to the tank will cause erratic level readings. When filling an empty tank be sure to bleed the pipe connection at the transmitter to avoid this problem. Also bleed the connection if the tank is refilled after it was drained below the 16-inch level.
INSTALLING A NEW TRANSMITTER
All new transmitters must be programmed at the Heatec factory using special Siemens software configured for Heatec tanks.
Only two settings can be reset in the field. One is the Full Scale Blind setting, which should be set according to the specific gravity of the fuel as explained earlier.
The other is the zero setting. This setting corrects for transmitter tilt. The transmitter is normally tilted upwards for easy reading when it is installed on the tank at Heatec. If you change this tilt, you should reset the zero setting according to instructions in the Siemens manual, under the heading 6.2.5 Zero Adjustment (Position Correction).
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Figure 7. Fill Levels With Allowance For Expansion
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Tank Capacity
(gallons)
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Tank Height (feet)
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Maximum fill level
(feet)
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6500
|
10
|
9.0
|
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13000
|
20
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18.0
|
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20000
|
30
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27.0
|
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23000
|
35
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31.5
|
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Figure 8. How Fuel Volumes (gallons) Change
With Changes In Fuel Temperature
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30 Deg F
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40 Deg F
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50 Deg F
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60 Deg F
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70 Deg F
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80 Deg F
|
90 Deg F
|
100 Deg F
|
|
6442
|
6461
|
6481
|
6500
|
6520
|
6539
|
6559
|
6578
|
|
12883
|
12922
|
12961
|
13000
|
13039
|
13078
|
13117
|
13157
|
|
19821
|
19880
|
19940
|
20000
|
20060
|
20120
|
20181
|
20241
|
|
22794
|
22862
|
22931
|
23000
|
23069
|
23138
|
23208
|
23277
|