Long range ultrasonic testing (lrut)

Long Range Ultrasonic Testing – NDT Inspection Technique

Long Range Ultrasonic Testing is an advanced technology for detecting and analysing corrosion where access is difficult.

Benefits

• Low cost screening with 100% coverage

• Focussing capability to evaluate corrosion distribution around pipe circumference

• Typical test range 60m from single location, ideal conditions can achieve longer distance.

• Testing of pipes up to 48” diameter

• Proven capability on pipe in service up to 125 oC

• Detection of metal loss > 3%

• Ideal where conventional testing is impossible or very costly e.g. clamped,insulated, elevated, sleeved or buried pipes.

Process

• Low frequency ultrasound is transmitted and received from a single location

• The guided waves used travel long distances, even in buried, submerged or insulated pipe

• Reponse from flaws is a function of their depth and circumferential extent

• Focussing allows ultrasound energy to be concentrated into a small region of pipe for detailed localised inspection

• Teletest® uses ‘multi-mode’ technology to characterise and quantify any flaw detected

• A laptop PC runs dedicated Teletest® data acquisition and analysis software. The flaw detector communicates with the PC via a high-speed data link

Applications

Pipe Types

• Seamless

• Longitudinally and spiral welded

Pipe Materials

• Ferritic and stainless steels

• Other metals

Pipe Situations

• Buried

• Air-to-soil interface

• Air-to-water interface

• Elevated on racks

• Sleeved in road crossings

• Wall, bund or berm penetrations

Flaws Found

• External corrosion

• Corrosion under insulation (CUI)

• Internal corrosion or erosion

Pipe Coatings Etc.

• Foam or mineral wool

• PVC, epoxy, coal tar epoxy

• Paint

• Bitumastic wrapping

• Transmission and distribution lines

• Refinery and Chemical plant

• Offshore risers

• Jetty lines

• Tank farm link lines

• Power plant service pipe

• Storage sphere support legs

• Headers