INTERNAL ROTATORY INSPECTION SYSTEM (IRIS)
Internal Rotary Inspection system(IRIS) is an ultrasonic method for the nondestructive testing of pipes and tubes.The IRIS probe is inserted into a tube that is flooded with water,and the probe is pulled out slowly as the data is displayed and recorded.The ultrasonic beam allows detection of metal loss from the inside and outside of the tube wall.
- A transducer located inside a turbine generates an ultrasound pulse along the axis of the tube
- The ultrasound is reflected on a 450 mirror and oriented toward the tube wall thickness
- The ultrasound is partially reflected on the ID, then transmitted inside the wall, and finally reflected on the OD
- Knowing the ultrasound velocity in the tube material, the wall thickness can be calculated by using the time of flight difference between the OD and ID echoes
- A water flow is going inside the cable and then through the turbine
- The mirror, attached to the rotor part of the turbine, rotates continuously at a speed of about 50 rev/s
- This rotation allow a full inspection of the tube wall thickness
- A small pin attached to the turbine body produces an ultrasound reflection each time the mirror passes under it
- The reflection from the pin is used to synchronize the screen display
IRIS Applications :
- Allows for the detection and sizing of wall loss as a result of corrosion, erosion, tube-to-tube wear, pitting, cracking and baffle cuts.
- Focused ultrasonic probe and a rotating mirror to produce a helical scan.
- Ultrasound is reflected from the tube ID and OD and the time difference is used to calculate the thickness.
- IRIS is a great backup and verification tool for the other tube inspection techniques.
- IRIS data to be presented as a B, C, or D-scan image.