API

API standards cover the petroleum industry's specific hardware and hazards: storage tanks, centrifugal pumps and compressors for process service, wellhead and pipeline equipment, and the in-service inspection codes by which operating facilities assess piping, vessels and tanks through their lives. Ownership of the in-service layer is what distinguishes the API corpus — it governs not only how equipment is built but how the installed base is inspected, evaluated and kept running, which makes it as much an operations library as a construction one.

Adoption is by industry gravity rather than law: an oil and gas project in any hemisphere will specify API equipment standards because operators, contractors and vendors all speak them, and vendor product lines are built to them. The standards then coexist with local legal regimes — national industrial-safety rules, union technical regulations — and the project carries both: API as the contractual technical basis, local law as the compliance floor, reconciled explicitly where they address the same equipment differently.