Tag
#b313
3 topics across all disciplines.
Examination extent and progressive sampling — what five per cent actually obliges
How fluid service sets the amount of examination, why the sample has to represent each welder on each procedure, and the progressive sampling rule that turns one rejected weld into a widening scope — the part of Chapter VI taught almost nowhere.
Joint preparation and fit-up — the hold point you only get once
Bevels and root gaps, internal misalignment and the limits on it, why trimming or counterboring is allowed where grinding the bore is not, tack welds as part of the final weld, and what an inspector checks in the minutes before the root goes in.
Preheat and post-weld heat treatment — hydrogen, hardness, and reading the chart
What preheat is actually for, why interpass temperature has a ceiling as well as a floor, when PWHT is required and when it may be exempted, how to read a chart recorder trace against the specified cycle, and the hardness survey that decides it in sour service.