LPG quantity calculation from liquid density
ADM003GVAE1005 301
DENL15 - liquid density at 15°C (kg/m
3
)
Step 3
Calculation of VCF and hence liquid density at tank conditions may be calculated
as follows:
VCF should be rounded to 5 decimal places.
The density of liquid at liquid temperature is given by:
DENL = DEN15 x VCF
Step 4
The following formulae are used for making corrections to liquid level gauges:
(a) Float buoyancy correction. This is necessary to correct for changes in liquid
density between calibration and use. The correction is achieved as:
Where:
X = (DENL15 - 500)/25
Yl =
0.296 - 0.2395 x X + 0.2449167 x X
2
-0.105 x X
3
+ 0.01658334 x X
4
Y2 =
363.8 + 4.924927 x X + 13.66258 x X
2
- 6.375 x X
3
+ 1.087503 x X
4
TR = 288.2 / Y2
TT = (1 - TR) ^ (1 / 3)
V0 =
1 - 1.52816 x TT + 1.43907 x TT
2
- 0.81446 x TT
3
+ 0.190454 x TT
4
VD =
(-0.296123 + 0.386914 x TR - 0.427258 x TR
2
- 0.0480645 x TR
3
) / (TR - 1.00001)
V1 = V0 x (1 - Y1 x VD)
TR = (TL + 273.2) / Y2
TT = (1 - TR) ^ (1 / 3)
V0 =
1 - 1.52816 x TT + 1.43907 x TT
2
- 0.81446 x TT
3
+ 0.190454 x TT
4
VD =
(-0.296123 + 0.386914 x TR - O.427258 x TR
2
- 0.0480645 x TR
3
) / (TR - 1.00001)
V2 = V0 x (1 - Y1 x VD)
VCF = V1 / V2
Δh
1
= correction to the gauge readout
for float buoyancy in mm
m mass of float in grams
d diameter of float in mm
Δh
1
1.273 10
6
×
m
d
2
-----
×
1
P
---
1
P
1
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–
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