Ultrasonic Inspection of Weld Seams in Spirally Welded Pipes
Main Features
Ultrasonic system for inspection of weld seams in spirally welded pipes complies with requirements of API5L, incl. SHELL extension, and comparable specifications.
Multi-channel ultrasonic inspection system is specifically designed for automatic equipment requiring a massive number of transducers as well as intensive data processing.
An automatic ultrasonic inspection system has been developed by the STARMANS Electronics Ltd., Prague, Czech Republic.
The complete inspection system consists of several blocks according to the prescribed requirements, namely of the electromechanical control subsystem and ultrasonic processing subsystem. General system architecture is modular, mounted in 19” rack for simple service and extension. The system is controlled from PC and external PLC.
The system can be equipped up to 32 independent channels for full inspection of weld metal and heat affected zone (HAZ).
The complete system utilizes DIO2000 ultrasonic channels combined in 19” rack with power supply, motion controllers and industrial PC.
Electro-Mechanical Control Subsystem
The electro-mechanical control subsystem consists of a control PC and programmable logic controllers based on FPGA with downloadable firmware.
During normal inspection process, the PC archives data and controls the mechanical operation of the system and other auxiliary functions via external PLC.
The mechanical operation of the system can be summarized as follows:
- Weld tracking system moving with head using horizontal linear rail with servo motor.
- Weld searching system search automatically weld by rotating tube.
- Protects transducers within the UT head.
- Enables transducer positioning for different diameter of pipe using flexibly adjustable mechanic system around the pipe diameter.
Testing Head with Probe Holders
Ultrasonic inspection system may be equipped with two testing heads for 10 to 18 ultrasonic transducers on each – depending on pipe O.D. and wall thickness. Transducers arrangement is very flexible, allowing all “K”, “X”, “I” configurations and their combinations for weld inspection.
Weld Tracking
Using a linear laser beam and a CCD camera, a correction of the spiral movement (rotational speed) is processed by the PLC to keep the UT head in a constant position relative to the weld center line.
PC Subsystem
The main processing system is based on ultrasonic channel units. Industrial (personal) computer PC receives the data packets from the real-time hardware DIO2000 and displaying indications of potential flaws.
Personal computer involved to setting all ultrasonic testing parameters and parameters for coordinates of transducers and marking.
PC computer involves:
• Standard database editing to add new rules to the database or remove obsolete ones.
• Review of past inspections; recall the inspection results of any already inspected pipe.
• System calibration. In this mode of operation, an inspection is run over a reference pipe with artificial flaws.
• Operation inspection.
• Access administration and password control.
Features of PC Subsystem
- All parameters in each channel are set-up individually.
- Each channel is activated or deactivated independently.
- Ultrasonic A-scan of each channel is displayed in one or several windows.
- The course of the values measured is being displayed graphically in dependence on time or space coordinates.
- Coordinates is selectable to spiral or length axis.
- Position of defect is displayed to length coordinate, independently on actual positions of probes.
- Outputs for automated delayed markers.
The results of calibration and inspection are being saved in ultrasonic system storage, edited on the screen display and printed.
An example of the test results
An example of the database record
Ultrasonic Subsystem
System consists of 18 identical ultrasonic channel units DIO2000.
All the ultrasound processing hardware is arranged in a 19” rack with modules of boards with dimensions 100x160 mm.
All settings of ultrasonic testing parameters, acoustic feedbacks checking, “X” or “K” testing configuration, channels timing, PRF control etc., are achieved using software configurations only.
Block Diagram of the System
