SERVICES >> ADVANCED NDT HEAD E&B TUBES

Internal Rotating inspection System (IRIS)

IRIS is a pulse-echo based tube inspection technique. A transducer excited by a high frequency pulse producers an ultrasonic wave that propagates into water. A mirror deflects the wave to produce a normal incidence beam on the inner diameter (ID) of the tube. Echoes reflected from each metal water interface are digitized and processed to extract the time of flight and amplitude of the frontwall and backwall echoes. Further processing is applied to calculate the tube ID, outer diameter (OD) and wall thickness (WT).

Complete tube inspection is obtained by rotating the mirror. A hydraulic turbine (IRIS) or an electric motor produces the driving force. Synchronization of the rotation can be obtained by various methods like ultrasonic targets or encoders.

The Olympus MS5800 IRIS system can accommodate these synchronization modes in order to display in real time, the data either on a cross-section thickness display (B-scan), or as a surface area thickness map (C-scan).

IRIS- Applications / Capabilities

IRIS can be applied on all types of heat exchanger and boiler tube materials.
It can be applied on tubes with diameter of 0.75 inch and thickness greater than 1 mm for best results

Advantages

Only technique that gives exact tube wall thickness
Will provide information on flaw profile and location i.e. if present on the ID or OD of the tube
With real time C-scan capabilities during data collection, pits as small as 1 mm diameter can be easily detected

Limitations

Very slow speed of operation
Requires extensive tube cleaning
Limited to minimum wall thickness measurement of 0.8mm for Carbon steel tubes

Signal Display