Tag
#corrosion
9 topics across all disciplines.
Pipe materials — what the grade on the spec actually means
A106, A312, P11 — how to read a piping material grade, why carbon steel is the default, and what forces an upgrade to alloy or stainless.
Plate materials — what vessels and tanks are actually made from
A516, A240, Monel, Hastelloy and titanium — why a plate specification is not a pipe specification, what each alloy is bought to survive, and why you almost never buy a solid exotic vessel.
Special piping components — the places that do not corrode like the pipe
Why dead legs, injection points, mixing points, soil-to-air interfaces and small-bore connections are pulled out of ordinary piping circuits, what each one actually suffers from, and why a healthy reading on the parent line tells you nothing about any of them.
Insulation, tracing and coatings — the layers outside the pipe
Four different reasons to insulate and why confusing them causes corrosion, how steam and electric tracing differ, why tracing fails silently, and why surface preparation is most of a paint system.
Material degradation — sensitisation, hardness limits and galvanic attack
Why welding can ruin the corrosion resistance of stainless steel without touching the weld, what the three conditions for galvanic corrosion are and which one to break, why sour service controls hardness rather than strength, what carbon equivalent predicts, and why zinc and stainless are kept apart.
Corrosion control documents — writing down why the plant corrodes
What a CCD is for, what API 970 expects it to contain, what happens in a corrosion workshop and why the operators in the room change the answer, and why a document written once and never reopened has already failed.
Integrity operating windows — limits that protect the metal, not the product
What an IOW is and how it differs from a process alarm or a safety trip, the three tiers in API 584, why an exceedance invalidates the inspection plan rather than causing immediate failure, and why windows nobody implemented are the usual outcome.
Risk-based inspection — deciding what to inspect, and how often
Why nobody inspects everything equally, how likelihood and consequence combine into an inspection plan, why naming the damage mechanism is the whole job, and the ways an RBI programme quietly goes wrong.
Inspecting and repairing structures — the other forty years
Construction is a small part of a plant's life. What degrades, why the worst mechanisms are the hidden ones, how risk-based inspection decides where to look, and why structures quietly become overloaded.