A tank, abbreviated as TK, is used to store volumes of fluids for storage or as part of a process.
- API Std 620 - Standard for Design and Construction of Large, welded, Low-pressure Storage Tanks
- API Std 650 - Standard for Welded Steel Tanks for Oil Storage
- API RP 651 - Recommended Practice for Cathodic Protection of Aboveground Storage Tanks
- API RP 652 - Recommended Practice for Cathodic Protection of Aboveground Storage Tanks
- API Std 653 - Standard for Tank Inspection, Repair, Alteration, and Reconstruction
- API Std 2000 - Standard for Venting Atmospheric and Low-pressure Storage Tanks: Nonrefrigerated and Refrigerated
- API Std 2015 - Standard for Requirements for Safe Entry and Cleaning of Petroleum Storage Tanks