Tag
#mechanical
7 topics across all disciplines.
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.
Non-destructive examination — choosing the method and reading the result
Why every NDE method is blind to something, what magnetic particle cannot do on stainless, why ultrasonics can miss a crack lying the wrong way, the difference between an indication and a defect, and why the examiner's qualification is part of the result.
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 loops and piping circuits — the two groupings an RBI study is built on
Why a corrosion loop and a piping circuit are different things, how each one is drawn and bounded, what goes wrong when a circuit is too big or a loop mixes two streams, and why every number downstream depends on getting these right.
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.
Running an RBI assessment — from data to an inspection plan that happens
How probability and consequence of failure are actually estimated, why inventory group and detection time decide consequence more than vessel size does, what inspection effectiveness really changes, and why most RBI programmes fail after the study rather than during it.