Proper sizing of the vapor recovery equipment can be a daunting task. The most accurate way is to calculate the flash point of each component in the oil stream in relation to flow, ambient temperature, size of vessels, and delta P into the storage.

The conventional wisdom is to size the vru at 1.5 – 2 times the estimated volume required to allow for unknowns, such as temperature fluctuations and future oil production which may be added to the battery.