API 650: Welded Tanks for Oil Storage, 13th Edition (2020)

API 650: Welded Tanks for Oil Storage, 13th Edition (2020) sets the standard for the design, construction, and inspection of vertical, cylindrical, aboveground welded storage tanks operating near atmospheric pressure. Intended for non-refrigerated service up to 93°C (200°F), this specification is essential for tanks used in the storage of petroleum, chemicals, and other liquid products.

Highlights:

• Covers open-top and closed-top tank design for a wide range of capacities
• Allows construction using carbon steel, stainless steel, and duplex steel materials
• Specifies requirements for shell, bottom, roof, nozzle components, and structural supports
• Provides detailed material selection guidance and limits for plates, flanges, and welding consumables
• Defines procedures for welding, welder qualification, and weld inspection
• Includes standards for erection, hydrostatic testing, tolerances, and repair methods
• Annexes address specialized applications:
  • Seismic design (Annex E)
  • Floating roofs (Annexes C and H)
  • Aluminum and stainless steel tanks (Annexes AL and S)
  • Elevated temperature service (Annex M)
  • Leak detection, under-bottom connections (Annexes I and O)
  • API Monogram licensing (Annex Y)

Who It’s For:
A critical reference for storage tank engineers, fabricators, inspectors, and facility operators involved in tank design, procurement, fabrication, and field erection in the oil, gas, chemical, and industrial sectors.

API 650-2020