Uninsulated Tanks

Where:

TS = Tank shell temperature

K = Ambient/Liquid weighting factor

TL = Temperature of liquid in tank

TA = Ambient temperature

The value of K can vary between 2.5 and 30 for extreme conditions of wind and viscosity. For most observations K is between 5 and 10. The API Manual (1995) Chapter 2 – Tank Calibration (Section 2A) states that a value of 7 for K, which can introduce a minor bias in extreme cases, is considered accurate.

The equation then becomes: