ROSEN Group is able to supply cutting edge inspection tools for customers who have to conduct inspections when extreme operating conditions converge.
One such product is the company’s offshore riser inspection solution for 18 inch pipelines.
The technology uses something called Time of Flight Diffraction (TOFD) to detect and provide accurate data on axial and circumferential cracks.
TOFD utilises ultrasonic technology to detect and quantitively size these cracks in pipelines with precision.
While pulse-echo methods involve sensors that perform double-duty as both transmitters and receivers, TOFD uses paired sensors, with once sensor acting as a transmitter and the other acting as a receiver.
The system emits broadband longitudinal ultrasonic waves to generate a sound field that is recorded and evaluated.
By comparing the shortest and longest sound path, the system determines whether or not there is a defect in the material of the pipe.
Defects, such as cracks, will reflect sound back to the receiver that does not match up with the signal from either the transmitter (the shortest sound path) or the back wall (the longest). This anomalous signal is called the ‘diffraction wave’.
Video: ROSEN Group.
The whole system is connected with a live tether, meaning it has a consistent, unlimited power source and is able to transmit inspection data in real time.
It also includes a crawler module that can be controlled remotely both forwards and backwards, and allows operators to adjust speed as needed to successfully complete inspection operations as needed.
For more information, visit ROSEN’s website.