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Gas Cargo Calculationexercise

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Cargo in tanks 2 Ps & Sb

Tanks are loaded with Propylene Soundings (ENRAF gauges)

Tank pressure: 2.60 barg

Patm: 995 mb

2Ps 2Sb

7352mm 7480mm

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Cargo tank temperatures

Ships data

Trim: 1.5 meters by the stern

List: 0.5 to Sb

2Ps 2Sb

-15.5 -16

-24.2 -24.7

-23.9 -23.8

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Height of the tank 10.50m (Ps & Sb)

100% capacity 1400.35 m3

each tank

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Calculation average liquid and

gas temperature

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Correction of soundings

Dip = Thermal Contraction or

expansion of the measuring tape

Float = Correction for change in float

immersion for different densities

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Correction for trim & list

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Calculation actual volume &

mass in the liquid phase

Liquid volume x shrinking factor x

liquid density

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Calculation gas height &

Weighed average tanktemperature

Weighed average tank temperature =((liquid height x liquid temp.) + (gas

height x gas temp.))/Total height of the

tank.Used to obtain the shrinkage factor for the

complete tank

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Weighed Av.temp. Ps: ((7412mm x -

24.05C) + (3088mm x -15.5))/10500 = -

21.53

Weighed Av.temp. Sb: ((7543mm x -

24.25C) + (2937mm x -16.0))/10500 = -

21.89

(-21.53 -21.89)/2 = - 21.71

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Calculation of the gas density

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Final result

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