Hello all,


We had some problems this summer to calculate quantity of cargo for oil tanker. The cargo of Decant Oil with API gravity -4 (minus). We had a required metric tones and needed to calculate standard and observed volume to load the tanker. The ASTM/API tables does not work with negative API.

Initial data:
Cargo - Decant Oil
API - "-4"
Temp - 50 deg. Cels.
Weight - 20000mt

Required:

Gross observed volume (GOV) - ?
Gross standard volume (GSV) - ? @60deg. F

Could anybody please explain the correct way for such calculations? What tables/data should we use? Does the calculation differ from crude oil calculations?

Many thanks to You
and Best Regards.