Iso 21457 Materials Selection And Corrosion Control For Oil And Pdf _verified_ Instant

| Control Method | Typical Application | ISO 21457 Reference | |----------------|----------------------|----------------------| | Corrosion inhibitor | Carbon steel flowlines | Clause 6.3.2 | | CRA cladding | Separators, vessel nozzles | Clause 5.4 | | Non-metallic liners | Acid service, low pressure | Clause 5.6 | | CP + coating | External pipelines, risers | Clause 6.4 |

When bulk CRA is too expensive, ISO 21457 endorses: | Control Method | Typical Application | ISO

The standard helps engineers answer the critical economic question: “Is it cheaper to use carbon steel with inhibitors, or invest in expensive alloys upfront?” | | Corrosion Mechanisms Addressed | CO₂ corrosion,

| Principle | Description | |-----------|-------------| | | Not all materials need the same level of corrosion allowance; life-cycle cost vs. risk. | | Material Classes | Carbon steel, CRA (Corrosion Resistant Alloys - e.g., SS 316, duplex, Inconel), non-metallics. | | Corrosion Mechanisms Addressed | CO₂ corrosion, H₂S (SSC/SWC), O₂ ingress, MIC (Microbiologically Influenced Corrosion), erosion-corrosion, galvanic corrosion. | | Design Life Integration | Materials chosen for 5, 10, 25+ year life with or without corrosion allowance. | MIC (Microbiologically Influenced Corrosion)

ISO 21457 requires that for HPHT wells (>150°C and >1000 bar), the standard tables are not sufficient – you must perform qualification testing.