The most widely employed technique for weld inspection has been since its introduction the RADIOGRAPHIC (RT) examination supported, when required, by ULTRASONIC (UT) examination for detection and evaluation of structural and critical defects which are difficult to detect with radiographic examination (planar defects).

Signal processing and digitising technology has made significant steps ahead and now sophisticated computer aided instruments permit the complete recording of UT examination.

The first edition of CODE CASE 2235 has stated since 1999 the possibility of replacing Radiography in weld inspection, defining the minimum requirement of the UT system and method employed. With revision 6 the manufacturer can replace RT on weld thickness from ½” to and over 12”

The main benefits for the manufacturer are:

• Avoid to use radioactive materials or Xray equipment
• Elimination of consumables costs (films, developers etc...)
• Reduction of material handling to and from the X-Ray bunker or area
• Real time results during operation
• Reliable test on heavy thickness

From the quality point of view, a UT examination according to CODE CASE 2235-6 performs the best probability of detection (POD) and can be the most accurate defect sizing tool. Such test can be reliably repeated on site so that this technique is extremely powerful as a pre-service inspection.

Our approach is based on two different techniques:

• TOFDT (Time Of Flight Diffraction Technique) in combinazione con pulse-echo.
• Pulse-echo con scansione registrata

Main applications are:

¨        Automatic UT inspection with scanner and TOFDT

¨        Automatic UT Inspection of tube to plate welds in Heat exchangers and Urea Strippers