We run RT, DR and CR crews too. Credibility means telling you where they beat ultrasonics — so here’s the actual decision, weld by weld:
Every weld on the job
Any “yes” points to radiography for that weld: code or spec mandates RT film (RT — we shoot it, and can pair it with PAUT); volumetric-dominant thin-wall / shop welds (RT / DR — porosity & slag image beautifully); geometry blocks the scanner path (RT, or semi-automated PAUT where a band scanner cannot couple); surface prep impossible (RT may be it — or qualify a UT technique for the as-found surface condition). Otherwise AUT / PAUT is the primary method.
On 48-in., over-1-in. wall mainline girth welds, none of these gates typically applies on production welds — which is exactly why AUT/PAUT is the right primary method, with RT held in reserve for the exceptions.
