NON DISTRUCTIVE TESTING - HEAT TREATMENT - PLANT INSPECTION

PAUT - Tofd & Phased Array

PHASED ARRAY & TOFD

Phased array technology uses multiple ultrasonic elements and electronic time delays to create beams that can be steered, scanned, swept, and focused electronically for fast inspection, full data storage, and multiple angle inspections.

Phased array technology provides precise measurement with the most reliable results.

The phased array technique is an advanced inspection  ultrasonic method used by Italsabi to check bolts and studs, among other assembling pieces.

This technique allows a company to detect signs of corrosion, providing clear images that reflect the condition of the bolt thread.

The bolts no longer need to be disassembled to be inspected properly. Thanks to the phased array technique, scans can be captured and stored for offline interpretation and the technique permits accurate, repeatable inspections for monitoring known defects. Bolt inspection is an in-service inspection application and therefore does not result in downtime of equipment and personnel.

This type of inspection involves a scanner with a phased array probe that is attached to the head or end of a bolt, which is then “blasted” with ultrasound. By means of a sector scan, we can visualise the possible defects for these bolts.

Any corrosion-related degradation of the thread can be observed, as well as any corrosion on the shaft of the bolt. Indications will be visible when they are shaped as linear indications between the toes of the thread.

The phased array technique has multiple applications. For instance, it can be used on crank bolts on taps, where the pieces cannot be disassembled. It can also be used to identify corrosion on bolts or studs that cannot be visually inspected, as well as on heat exchanger bolts. This technique is also useful for periodic surveys on installations with screw connections.

Italsabi Phased Array operators are qualified according to the ISO9712 level II & SNT TC 1A standards. 

Pros

Electronic (raster) scanning possible without moving the probe

Greater control of beam characteristics

Possibility of simultaneous inspection with multitude of angles using a probe

It can more easily inspect complex geometry or restricted access areas

It can replace expensive and dangerous radiographic applications

 

Advantages TOFD

Possibility of investigating a significant volumetric portion of the weld with a simple linear scan parallel to the weld, for discontinuities in any case oriented

Significantly reduces inspection times.