Abstract: In the paper an example taken is a failure of oil tank explosion in oil tank farm in Shujiang country. The explosion resulted from static electric charge was analysed. It is stated that the conditions to explosion involve oil flow in tank, accumulation of great quntities of static electric charge, any grounded metal conductor in tank, and a great amount of mixture of oil and gas. Point to the conditions above the measures for future design, install and imanagement are stated.