In the industrial and engineering sectors, API stands for the American Petroleum Institute, the leading trade association and standards-setting organisation for the oil, natural gas and petrochemical industries. API publishes rigorous, globally recognised engineering standards governing how critical process equipment is designed, built, tested and documented.
For rotating equipment, four standards matter most:
- API 610 — Centrifugal pumps. Covers centrifugal pumps for petroleum, petrochemical and natural gas service, including the OH, BB and VS type classifications.
- API 682 — Pump shaft sealing systems. Covers mechanical seals and seal support systems, defining seal categories, types (A, B and C) and arrangements (1, 2 and 3).
- API 612 — Special-purpose steam turbines. Covers steam turbines in continuous, critical, unspared service. API 611 covers general-purpose turbines in less critical duty.
- API 617 — Axial and centrifugal compressors and expander-compressors.
Specifying to an API standard is how a plant ensures equipment will meet the safety, integrity and efficiency expectations of heavy-duty process operation — and it is why API documentation is normally a condition of purchase in refinery service.