SAIS : Scotia Automated Inspection Systems : Productivity


Case Studies : Productivity

The most recent contract won by SAIS in this field was manufactured by Subsea7 at their fabrication yard in North Caithness, Scotland. The inner bundle consisted of 7 kilometres of 4”, 6”, 8” and 12” pipe welded simultaneously and requiring synchronized X-ray. The main challenge was the exceptionally high speed of production introduced by innovative mechanised welding processes, whilst maintaining the extremely high radiographic quality stipulated by the client specifications.
Our solution was to use Agfa f6 film with Agfa RCF screens, enabling us to reduce the exposure times to one tenth of the normal, and processing dry to dry at 2 minutes.		A combination of X-Ray crawler and double wall techniques were developed to meet the stringent requirements with such short exposures.
Over a 12 hour shift, the cycle time for four welds X-Rayed and interpreted averaged less than 7 minutes; often less than 6 minutes. To achieve the high degree of film and screen cleanliness required for this process, two new darkrooms were specially configured and deployed back to back. The overall process was rehearsed and studied over a period of days; finessed and improved until we could start the project with a high degree of confidence and success.