Tube inspection using massively parallel systems

The objective of the NDT procedure is to detect defects from the outside of the tube at very high speed. Known defects include loss of thickness, delaminations, and cracks (see figure below). The following schematic diagram illustrates the location and orientation of these defects.

In order to meet speed requirements, several inspection techniques are used in parallel rather than fired sequentially. NDT procedures are decomposed into:

  • thickness measurements, delamination detection
  • axial and skewed crack detection
  • circumferential crack detection (OD & ID defects)

The full inspection procedure is illustrated in the following schematic diagram:

The customer’s speed requirements are achieved by making all measurements for the tube inspection simultaneously using three fully parallel systems. This customized inspection system has been successfully implemented at the customer’s production site (see pictures below).

On-site implementation. Pictures show display-screen (left-hand photo), probes and coupling to the tube (top-left photo). The helicoidal motion controller is shown in the bottom-right picture. Work realized in collaboration with DMV (group Mannesmann) and CEV (VALLOUREC R&D Group).