There are innumerable welded tubes and pipes in the oil and gas industry. From manufacture through the entire service life of these welded parts, they must be inspected and monitored because of pressure and toxic contents. Magnetic particle inspections are frequently used, but this technique is limited to surface or breaking defects. X-ray technique is also used, but is time consuming and requires a safety zone around the inspection area.

For these reasons, the use of ultrasonic inspections using the OmniScan™ Phased Array unit, manual scanner and 64-element probe provides major benefits: the most precise results, best images, fast inspections, and a nonhazardous inspection technique.

Typical Inspection Requirements
• Tube or pipe from 2 in. to 60 in. OD
• Wall thickness from 5 mm to 25 mm
• Portable equipment
• ASME Code compliant

Type of Defects
• Crack
• Lack of fusion
• Lack of penetration
• Porosity
• Undercut
• Slag inclusion

Description of the Solution
• Circumferential inspection using a manual scanner with one encoder
• Linear scanning around the weld. Electronic scanning at 60 degrees, then 70 degrees for each side of the weld.
• Imaging of real-time Top C-scan, Side B-scan, and Sectorial scan (S-scan)
• Primary analysis done with the OmniScan
• Postanalysis performed with TomoView® software

Advantages of the Solution
• High inspection speed
• Portability of the equipment
• Encoded linear scanning
• Electronic scanning from phased-array probe allowing accurate location characterization and sizing of defects

Equipment Required
• OmniScan™ PA acquisition unit (Weld package)
• 5-MHz 64-element probe with 55-degree SW wedge
• Scanner
• Couplant system
• TomoView™ software for advanced analysis

Prior to any inspection conforming to the ASME code, a performance demonstration is required.

A zero-degree scan is performed on the near-weld material and the heat-affected zone (HAZ) to make sure the ultrasonic beam from the phased-array probe will penetrate the welded area properly. This scan is also used to find any laminations.

A first inspection is performed using a linear scan with an electronic scan using a 60-degree SW covering the complete volume of the weld. Then a second scan is made using a 70-degree SW. The same two angles are reused on the other side of the weld.

A first data analysis is made on the OmniScan™ after each scan. If an indication is found, the file is imported into TomoView™ where the indications are sized and characterized.