ASME standard · reference card
Does ASME B31.3 govern your piping, and which fluid service category sets the examination extent? Scope decision flow, the codes it invokes, and the records that evidence WPS compliance.
ASME B31.3 is a piping code, and most of what goes wrong with it traces back to one early decision: the fluid service category assigned to a line. That category, not the pipe schedule or the material alone, sets how much of the fabrication gets examined and to what extent.
The code does not qualify anything itself. Welders and procedures qualify to ASME Section IX, and B31.3 simply requires the qualification to exist and to match the material and process in front of you. Skipping that step because “the weld looks fine” leaves nothing for an Owner’s Inspector to check against.
Preheat compliance is the other quiet failure: it is a condition to be reached and held, not a value written on a traveler. Therness equipment measures it directly and ties it to the welding process record for every weld the random sample never examines.
| Question | If yes | If no |
|---|---|---|
| Is the piping process piping in a petroleum, chemical or similar process plant? | ASME B31.3 is the governing piping code. | Power piping goes to B31.1; other piping types have their own B31 book. |
| Has the line's fluid service category been assigned? | The examination extent and several material and design requirements follow from it. | Assign it before planning examination; reclassifying after welding is not something an inspection record fixes. |
| Are the welders and procedures qualified to ASME Section IX for this material and process? | Proceed with fabrication under the qualified procedure. | Qualify first; B31.3 qualifies procedures and welders through ASME Section IX, with its own additional requirements layered on top. |
| Did a random examination sample find a rejectable defect? | The examination scope expands progressively per the code's rule, not a one-off re-check of the single weld. | The originally set sampled examination extent stands. |
Conformity is decided by inspection and testing against the criteria the standard and the contract set. The records below are evidence that the process was held where it was qualified; they support an inspection result, they never replace one.
| Requirement | Record produced | Source |
|---|---|---|
| Demonstrating WPS compliance on every weld, not only the ones the random sample examines | Measured preheat, interpass temperature and heat input per pass, recorded continuously | WeldTrace |
| Confirming preheat was reached before arc-strike on materials that require it | Full-field thermal image of the joint immediately before welding | HeatCam IR-C |
| A per-weld record available to the Owner's Inspector alongside NDE reports | Timestamped, per-weld process export tied to welder and line identifier | HeatCore AI |
Therness records what the machine actually delivered on every weld — parameters, thermal signature and a per-weld trail — so a conformity argument rests on measurements instead of recollection.
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Priorità I, Obiettivo Specifico a), Azione 4 – "Sostegno alla nascita delle start up"
