A rectangular tank has a total depth of 21m and volume of 20600 m3, which includes of trunkway of depth 1m and volume 600m3. find the ullage when 16320 t of oil of RD 0.8 is loaded.

Given :

The total depth of tank =21m
Volume of the tank = 20600m³
The height of the trunkway = 1m
Volume of the trunkway =  600m³
Oil loaded = 16320t
RD= 0.8
The height of the tank = (21-1)
= 20m

Volume of the tank= (20600 – 600)
 =20000m³

Area of tank = (20000 /20)
=10000m²

Volume of the oil = (mass /density)
=(1620 /0.8)
= 20400 m³

Hence, Volume of the oil inside the trunkway = (Total volume of the oil – volume of the tank)
= (20400 – 20000)
 =400m³

Depth of the oil = (volume /area)
= (400/600)
 = 0.66m

Hence, Ullage = (1 -0.66)
                             = 0.33m