API Std 2015 PDF

This standard is applicable to stationary atmospheric low-pressure (up to and including 103 kPA (15 psig) aboveground petroleum storage tanks used in all sectors of the petroleum and petrochemical industry, including:
•    crude oil and gas production;
•    refining;
•    petrochemicals;
•    pipelines and terminals;
•    bulk storage;
•    ethanol facilities.
This standard provides requirements for safely planning, coordinating, and conducting tank entry and cleaning operations, from removal from service through return to service.

This standard does not and cannot cover every possible unique hazard or situation that may arise during tank-cleaning operations. Site, product, and tank-specific hazards and situations shall be addressed by employers using the appropriate principles and considerations provided for by this standard.

This standard does not apply to the following types of tanks or vessels:  
•    pressure vessels and pressurized tanks exceeding 103 kPa (15 psig);
•    cryogenic or refrigerated vessels or pressure tanks;
•    vessels and tanks maintained under a vacuum;
•    process vessels;
•    underground storage tanks. 
Although API Standard 2015 is not intended to cover these types of tanks and vessels, many of the safe tank-cleaning and entry principles and requirements in this standard apply and should be considered.