API 650 covers design and construction of aboveground welded storage tanks operating at atmospheric pressure.
Pressure: Up to 2.5 psi
Tank Type: Vertical cylindrical
Fluids: Crude oil, diesel, chemicals
Roof Types: Fixed, floating
Diameter: Up to 100m+
Foundation: API Annex B
API 620 is used for low-pressure storage tanks including cryogenic applications.
Pressure: 0 – 15 psi
Temperature: Down to -198°C
Applications: LNG, LPG, Ammonia
Annex: Q & R for cryogenic tanks
API 660 defines requirements for shell-and-tube heat exchangers used in oil & gas and petrochemical industries.
API 661 covers fin-fan coolers used for cooling process fluids using ambient air.
TEMA standards define mechanical design, tolerances, and classifications for shell-and-tube heat exchangers.
| Class | Application | Service |
|---|---|---|
| R | Petroleum | Severe service |
| C | General | Moderate service |
| B | Chemical | Intermediate |