Inspection Services :: Piglet® 'umbillical'
A. Hak Industrial Services has developed the world-patented Piglet® inspection system especially for most of the so called “non-piggable” pipelines where conventional pigging is not possible. The Piglet® communicates via glass fibre optics, which enables on-line monitoring of the inspection data. This system combines the advantages of ‘free swimming’ inspection systems with the advantages of ‘cable operated’ inspection systems, whereby the disadvantages of both have been eliminated. Furthermore the system is suitable for passing small radius bends, mitre-bends, multiple diameters etc. and is bi-directional.
The Piglet system has the ability to inspect pipeline lengths of over 12km in one run, negotiate an unlimited number of bends and travel in two directions (bi-directional). In addition it has the ability to inspect multiple diameters in one run, provide all ultrasonic measurements online and save the raw ultrasonic data for detailed post processing analysis.
The Piglet inspection system is equipped with a special ‘umbilical’ storage facility that holds a glass fibre optic cable,. which is placed on an unwinding reel stored in the Piglet inspection system itself. The Piglet inspection system is equipped with a measuring device that uses ultrasound waves for measuring the wall thickness and inner radius of the pipe. A sound pulse is send from the transducer in the middle of the pipe in the direction of the pipe wall. The sound pulses generated by the transducer are reflected towards the pipe wall via a rotating mirror, which enables measurements to be taken of the complete circumference of the pipe. Depending on the diameter of the pipeline (and therefore the surface to be inspected), the travelling speed of the Piglet through the pipe is adjusted to provide 100% scan coverage, ranging from 200 m/hr to 1 km/hr.
While the Piglet progresses through the pipeline, all raw data gathered is transmitted to an on-line computerized data acquisition system which shows the actual wall thickness and an initial discrimination between internal and external corrosion. This allows both the inspection engineers as well as the pipeline owner to obtain a first impression on the condition of the pipeline. In addition, an advanced data acquisition system stores all data simultaneously on hard-disc, which allows for detailed post processing, resulting in the most accurate and detailed ultrasonic analysis of the inspected pipeline(s) available in the industry. This post processing may start immediately after the inspection has finished.
The Piglet® 'umbillical' consist of various modules which can be built together into one single bi-drectional pig, generally for larger pipe diameters or mounted as separate modules for smaller pipe diameters:
- Pig transmitter
- UT measuring head
- Electronics
- Odo-meter
- Battery unit
- Glass fibre unit
The data acquisition unit is used for capturing and storing the inspection data and enabling control of the Piglet®, where the software (Tube Inspector) uses the ultrasonic C-scans, speed, distance and rotation in its analysis. This system combines the advantages of ‘free swimming’ inspection systems with the advantages of ‘cable operated’ inspection systems, whereby the disadvantages of both have been eliminated. The system has the ability to:
- Inspect pipeline lengths up to 12 km in one run
- Negotiate an unlimited number of bends
- Travel in two directions (bi-directional)
- Inspect multiple diameters in one run
- Provide all ultrasonic measurements online.