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Selecting the Correct High Temperature UT Couplant

When performing UT inspections at elevated temperatures, it is critical to select the correct couplant, both for performance and safety.  Thickness gauging and corrosion mapping are often conducted at temperatures between 500°and 1000°F (260° and 538°C) where auto-ignition may occur.  Ultrasonic transducers and instruments capable of operating at temperatures up to 950°F (510°C) are routinely used, and development programs are targeting new designs with capabilities up to 1100°F (593°C).

Auto-ignition of ultrasound couplants has increased exponentially over the past decade due to higher temperature inspections, such as in heavy crude refining, and due to the extensive use of inspection ports.  The risk to inspectors and facilities, as well as the liability auto-ignitions impose can be reduced or eliminated by a few steps:

  1. Make certain all high-temperature ultrasonic couplants are labeled with the current manufacturer operating range and that inspectors are aware of the range.
  2. Check the temperature of the part, especially in ports and confined areas, before inspecting.  (Note: In confined spaces and inspection ports the temperature can be approximately 150˚F higher than on exposed pipe.)
  3. Select a couplant labeled for the intended operating range.
  4. Request and post the below adhesive backed sticker in a location where inspectors have access. Copies of the sticker are available at no charge by contacting 360.671.9121 or marian@echoultrasonics.com. 

Elimination of auto-ignition of ultrasonic couplants is one of the lowest cost, highest benefit actions you can take to protect inspectors, facilities and to reduce liabilities.

The operating range of Magnaflux/Sonotech Sono® 1100 has been reduced to 700 to 775°F with a restriction for use in ports to under 455°F (below the operating range of the couplant). A better replacement is EchoTherm Extreme with an operating range of -40 to 1250°F with NO limitations for port, confined space or under insulation UT inspections.

All Echo Ultrasonics high-temperature couplants are labeled with the operating range and auto-ignition temperature.  Echo’s couplant line includes:

Two couplants with an auto-ignition temperature above current UT equipment capabilities, no operating range restriction for ports, confined spaces or under insulation UT inspections:

  • EchoTherm Extreme: -40 to 1250°F (-40 to 675°C):
  • EchoTherm: 200 to 1000°F (93 to 538°C)

Two couplants with broad operating ranges, but require attention to the temperature in confined spaces and ports as the temperature can be approximately 150°F higher than on exposed pipe.

  • HiTempco: -50 to 775°F (-45 to 412°C)
  • VersaSonic: -10 to 700°F (-23 to 371°C)

Let us prove to you that Echo has a better high temperature couplant solution for safer, faster inspections. Request free samples today.