API STD 2015 pdf download.Requirements for Safe Entry and Cleaning of Petroleum Storage Tanks 1 General 1.1 SCOPE AND APPLICABILITY This standard is applicable to cleaning stationary atmo- spheric and low-pressure (up to and including 15 psig) above- ground petroleum storage tanks used in all sectors of the petroleum and petrochemical industry, including crude oil and gas production, refineries, petrochemical...